At the moment, if you want to fight evil as a Goblin or Worgen you need Cataclysm, and it seemed like pandas would only be for those willing to pay the fee to step through the Mists of Pandaria. But no. As of September 25th, any World of Warcraft player will be able to play as any of Azeroth's races from the start - though not all of its classes - regardless of whether you've bought any expansions.
That might seem a small detail - after all, if you play WoW, you probably have them all. Newer players attracted by the kung-fu Pandaren though are unlikely to be too impressed at being expected to buy three separate expansions that they may never even get high enough level to see properly. You won't however be able to create a Monk without the expansion, or Death Knights without Wrath of the Lich King, and will only get access to the new Wandering Isle starting area rather than Pandaria proper.
Needless to say though, a few pre-ordering fans at least aren't too happy at what they see as diminishing the expansion's value. "I genuinely only bought it to be a panda..." grumbles one. Aww...
