Lots of other aspects of the game have either changed or been extended. There are new badges to collect (including cooking badges that can reward you with new recipes), new fishing spots and fish, new mounts, new profession recipes, to name just a few. The more you delve into the expansion you discover how big the change has been. The huge amount of sales and the huge queues on servers indicate how successful these changes have been.
If you have a World of Warcraft account then this expansion is a must have. It lives up to all expectations and a lot more.