On internals@mysql a developer at IBM pointed out that DBTYPE needed to be removed from the example (its a single line which was needed for previous versions of MySQL). Its been removed. Added a couple of comments.

storage/example/ha_example.cc

@@ -79,6 +79,10 @@
   ha_example::open() would also have been necessary. Calls to
   ha_example::extra() are hints as to what will be occuring to the request.
 
+  A Longer Example can be found called the "Skeleton Engine" which can be 
+  found on TangentOrg. It has both an engine and a full build environment
+  for building a pluggable storage engine.
+
   Happy coding!<br>
     -Brian
 */
@@ -132,7 +136,6 @@ static int example_init_func(void *p)
                    (hash_get_key) example_get_key,0,0);
 
   example_hton->state=   SHOW_OPTION_YES;
-  example_hton->db_type= DB_TYPE_EXAMPLE_DB;
   example_hton->create=  example_create_handler;
   example_hton->flags=   HTON_CAN_RECREATE;
 

storage/example/plug.in

@@ -1,3 +1,3 @@
 MYSQL_STORAGE_ENGINE(example,,  [Example Storage Engine],
-        [Skeleton for Storage Engines for developers], [max,max-no-ndb])
+        [Example for Storage Engines for developers], [max,max-no-ndb])
 MYSQL_PLUGIN_DYNAMIC(example,   [ha_example.la])