Index: wp-includes/cache.php
===================================================================
--- wp-includes/cache.php	(revision 15325)
+++ wp-includes/cache.php	(working copy)
@@ -167,6 +167,19 @@
 }
 
 /**
+ * is wp_cache available?
+ *
+ * This function informs about wether or not the 
+ * cache is available.
+ *
+ * @return bool Cache Availablity.
+ */
+function wp_cache_available() {
+	global $wp_object_cache;
+	return !empty( $wp_object_cache ) && is_object( $wp_object_cache );
+}
+
+/**
  * Reset internal cache keys and structures.  If the cache backend uses global blog or site IDs as part of its cache keys,
  * this function instructs the backend to reset those keys and perform any cleanup since blog or site IDs have changed since cache init.
  *