Blizzard recently unveiled the highly-anticipated talent calculator for their upcoming expansion, Mists of Pandaria. Below you will find direct links to each of the classes. On the site you will find both talents and abilities for all classes ( Monk coming soon). This includes the new Guardian/Feral split for Druids.
Keep in mind the caveat offered on the site, however:
All specs, spells and talents are not final and may change during the development process.