Originally, HoF and Terrace were intended to launch together - the change in the schedule was made to stagger their releases more. Seems like a good idea to me, as it gives more chances to clear the new raids before the release of yet more content.
Mists of Pandaria is here! The level cap has been raised to 90, many players have returned to Azeroth, and pet battles are taking the world by storm. Keep an eye out for all of the latest news, and check out our comprehensive guide to Mists of Pandaria for everything you'll ever need to know.