diff --git a/includes/datastream.version.inc b/includes/datastream.version.inc
index ecef019d..91e8d295 100644
--- a/includes/datastream.version.inc
+++ b/includes/datastream.version.inc
@@ -231,6 +231,112 @@ function islandora_revert_datastream_version_form_submit(array $form, array &$fo
   $form_state['redirect'] = "islandora/object/{$islandora_object->id}/datastream/{$datastream_to_revert->id}/version";
 }
 
+/**
+ * The admin replace datastream form.
+ *
+ * @param array $form
+ *   The Drupal form.
+ * @param array $form_state
+ *   The Drupal form state.
+ * @param AbstractDatastream $datastream
+ *   The datastream to be updated.
+ *
+ * @return array
+ *   The drupal form definition.
+ */
+function islandora_datastream_version_replace_form($form, &$form_state, AbstractDatastream $datastream) {
+  module_load_include('inc', 'islandora', 'includes/content_model');
+  module_load_include('inc', 'islandora', 'includes/utilities');
+
+  $object = islandora_object_load($datastream->parent->id);
+  $form_state['object_id'] = $object->id;
+  $form_state['dsid'] = $datastream->id;
+  $form_state['object'] = $object;
+
+  $upload_size = min((int) ini_get('post_max_size'), (int) ini_get('upload_max_filesize'));
+  return array(
+    '#redirect' => "islandora/object/{$object->id}",
+    '#attributes' => array(
+      'enctype' => 'multipart/form-data',
+    ),
+    'dsid_fieldset' => array(
+      '#type' => 'fieldset',
+      '#title' => 'Update datastream with latest version',
+      '#collapsible' => FALSE,
+      '#collapsed' => FALSE,
+      'dsid' => array(
+        '#disabled' => TRUE,
+        '#default_value' => $datastream->id,
+        '#title' => 'Datastream ID',
+        '#description' => t("The current ID for this stream that is unique to this object."),
+        '#type' => 'textfield',
+        '#size' => 64,
+        '#maxlength' => 64,
+        '#required' => TRUE,
+      ),
+      'label' => array(
+        '#disabled' => TRUE,
+        '#default_value' => $datastream->label,
+        '#title' => 'Datastream Label',
+        '#required' => TRUE,
+        '#size' => 64,
+        '#maxlength' => 64,
+        '#description' => t('The DSID human-readable label'),
+        '#type' => 'textfield',
+      ),
+      'file' => array(
+        '#type' => 'managed_file',
+        '#required' => TRUE,
+        '#title' => t('Upload Document'),
+        '#size' => 48,
+        '#description' => t('Select a file to upload.<br/>Files must be less than <b>@size MB.</b>', array('@size' => $upload_size)),
+        '#default_value' => isset($form_state['values']['files']) ? $form_state['values']['files'] : NULL,
+        '#upload_location' => 'temporary://',
+        '#upload_validators' => array(
+          'file_validate_extensions' => array(NULL),
+          // Assume its specified in MB.
+          'file_validate_size' => array($upload_size * 1024 * 1024),
+        ),
+      ),
+      'submit' => array(
+        '#type' => 'submit',
+        '#value' => t('Add Contents'),
+      ),
+    ),
+  );
+}
+
+/**
+ * Submit handler for the replace datastream form.
+ *
+ * Adds a new datastream version as latest.
+ *
+ * @param array $form
+ *   The Drupal form.
+ * @param array $form_state
+ *   The Drupal form state.
+ */
+function islandora_datastream_version_replace_form_submit($form, &$form_state) {
+  $object = islandora_object_load($form_state['object_id']);
+  $form_state['redirect'] = "islandora/object/{$object->id}";
+  $file = file_load($form_state['values']['file']);
+  try {
+    $ds = $object[$form_state['dsid']];
+    $ds->label = $form_state['values']['label'];
+    $ds->mimetype = $file->filemime;
+    $path = drupal_realpath($file->uri);
+    $ds->setContentFromFile($path);
+    file_delete($file);
+  }
+  catch (exception $e) {
+    drupal_set_message(t('@message', array('@message' => check_plain($e->getMessage()))), 'error');
+    file_delete($file);
+    return;
+  }
+  drupal_set_message(t("Successfully Updated Datastream"));
+  $form_state['redirect'] = "islandora/object/{$object->id}";
+}
+
 /**
  * Gets Audit datastream values from foxml.
  *
diff --git a/islandora.module b/islandora.module
index 21c902c2..fafb7f8e 100644
--- a/islandora.module
+++ b/islandora.module
@@ -34,10 +34,11 @@ define('ISLANDORA_INGEST', 'ingest fedora objects');
 define('ISLANDORA_PURGE', 'delete fedora objects and datastreams');
 define('ISLANDORA_MANAGE_PROPERTIES', 'manage object properties');
 define('ISLANDORA_VIEW_DATASTREAM_HISTORY', 'view old datastream versions');
+define('ISLANDORA_ADD_NEW_DATASTREAM_VERSION', 'add a new datastream version as latest');
 define('ISLANDORA_MANAGE_DELETED_OBJECTS', 'manage deleted objects');
 define('ISLANDORA_REVERT_DATASTREAM', 'revert to old datastream');
 define('ISLANDORA_REGENERATE_DERIVATIVES', 'regenerate derivatives for an object');
-
+define('ISLANDORA_REPLACE_DATASTREAM', 'replace a datastream with new content, preserving version history');
 
 // Hooks.
 define('ISLANDORA_VIEW_HOOK', 'islandora_view_object');
@@ -317,6 +318,16 @@ function islandora_menu() {
     'access arguments' => array(ISLANDORA_VIEW_DATASTREAM_HISTORY, 4),
     'load arguments' => array(2),
   );
+  $items['islandora/object/%islandora_object/datastream/%islandora_datastream/replace'] = array(
+    'title' => 'Replace Datastream',
+    'page arguments' => array('islandora_datastream_version_replace_form', 4),
+    'page callback' => 'drupal_get_form',
+    'file' => 'includes/datastream.version.inc',
+    'type' => MENU_CALLBACK,
+    'access callback' => 'islandora_datastream_access',
+    'access arguments' => array(ISLANDORA_ADD_NEW_DATASTREAM_VERSION, 4),
+    'load arguments' => array(2),
+  );
   $items['islandora/object/%islandora_object/datastream/%islandora_datastream/version/%/delete'] = array(
     'title' => 'Delete datastream version',
     'page arguments' => array('islandora_delete_datastream_version_form', 4, 6),
@@ -516,6 +527,10 @@ function islandora_theme() {
       'file' => 'theme/theme.inc',
       'variables' => array('datastream' => NULL),
     ),
+    'islandora_datastream_replace_link' => array(
+      'file' => 'theme/theme.inc',
+      'variables' => array('datastream' => NULL),
+    ),
     'islandora_dublin_core_display' => array(
       'file' => 'theme/theme.inc',
       'template' => 'theme/islandora-dublin-core-display',
@@ -582,6 +597,10 @@ function islandora_permission() {
       'title' => t('View datastream history'),
       'description' => t('View all previous versions of a datastream.'),
     ),
+    ISLANDORA_ADD_NEW_DATASTREAM_VERSION => array(
+      'title' => t('Add datastream version'),
+      'description' => t('Add to a datastreams version history as latest.'),
+    ),
     ISLANDORA_REVERT_DATASTREAM => array(
       'title' => t('Revert datastream history'),
       'description' => t('Revert to a previous version of a datastream.'),
@@ -594,6 +613,10 @@ function islandora_permission() {
       'title' => t('Regenerate derivatives'),
       'description' => t('Regenerate derivatives for an object or per datastream.'),
     ),
+    ISLANDORA_REPLACE_DERIVATIVES => array(
+      'title' => t('Replace derivatives'),
+      'description' => t('Replace derivatives for an object or per datastream.'),
+    ),
   );
 }
 
@@ -1874,8 +1897,7 @@ function islandora_islandora_datastream_access($op, AbstractDatastream $datastre
     $hooks = islandora_invoke_hook_list(ISLANDORA_DERVIATIVE_CREATION_HOOK, $object->models, array($object));
     $hooks = islandora_filter_derivatives($hooks, array('force' => TRUE), $object);
     foreach ($hooks as $hook) {
-      if ($hook['destination_dsid'] == $datastream->id &&
-        (is_null($hook['source_dsid']) || islandora_datastream_access(ISLANDORA_VIEW_OBJECTS, $object[$hook['source_dsid']], $user))) {
+      if ($hook['destination_dsid'] == $datastream->id && islandora_datastream_access(ISLANDORA_VIEW_OBJECTS, $object[$hook['source_dsid']], $user)) {
         $applicable_hook = TRUE;
         break;
       }
diff --git a/theme/theme.inc b/theme/theme.inc
index feac06b2..a47c2062 100644
--- a/theme/theme.inc
+++ b/theme/theme.inc
@@ -23,6 +23,7 @@ function islandora_preprocess_islandora_default_edit(array &$variables) {
   $header[] = array('data' => t('Size'));
   if (user_access(ISLANDORA_VIEW_DATASTREAM_HISTORY)) {
     $header[] = array('data' => t('Versions'));
+    $header[] = array('data' => t('Replace'));
   }
 
   $header[] = array('data' => t('Operations'), 'colspan' => '4');
@@ -60,6 +61,13 @@ function islandora_preprocess_islandora_default_edit(array &$variables) {
           'datastream' => $ds,
         )),
       );
+      // Add new datastream content as the lastest version.
+      $row[] = array(
+        'class' => 'datastream-replace',
+        'data' => theme('islandora_datastream_replace_link', array(
+          'datastream' => $ds,
+        )),
+      );
     }
     $row[] = array(
       'class' => 'datastream-download',
@@ -436,6 +444,28 @@ function theme_islandora_datastream_version_link(array $vars) {
   }
 }
 
+/**
+ * Renders a link to take you to the datastream add latest version page.
+ *
+ * @param array $vars
+ *   An array containing:
+ *     - datastream: An AbstractDatastream to generate a new version.
+ *
+ * @return string
+ *   Markup.
+ */
+function theme_islandora_datastream_replace_link(array $vars) {
+  $datastream = $vars['datastream'];
+  //TODO: RELS-EXT and RELS-INT should never be replaced, but should
+  // be moved out into configuration somewhere. Hard coded === bad time.
+  if (islandora_datastream_access(ISLANDORA_REPLACE_DATASTREAM, $datastream) &&
+      islandora_datastream_access(ISLANDORA_ADD_NEW_DATASTREAM_VERSION, $datastream)) {
+    if (strcmp('RELS-EXT', $datastream->id) != 0 && strcmp('RELS-INT', $datastream->id) != 0) {
+      return l(t('replace'), "islandora/object/{$datastream->parent->id}/datastream/{$datastream->id}/replace");
+    }
+  }
+}
+
 /**
  * Renders a link that will re-create derivatives for a datastream.
  *