It was announced during the Mists of Pandaria Press Tour that mounts would become account-wide on release or in a patch shortly after. It looks like it will be release after all, and the feature is now available on beta (but heavily bugged).
I present to you, my mage riding my paladin's mount! (Obviously, we have no way to know if this is intended as part of the account-wide mounts)
Pandaren Voices now on Beta
Pandaren Voices are now also partially available on beta. For the moment only a few NPCs will talk to you but it should give you a good idea of where the game is headed for their voices.
Originally Posted by Blizzard Entertainment