World Of Warcraft Update 4.3 Will Be Last Major One Until Mists Of Pandaria

Blizzard has announced that the upcoming World of Warcraft update 4.3 will be the last major update until Mists of Pandaria launches.

Dave Kosak, the game's lead quest designer, speaking in a recent interview with Videogamer, stated that the update will be the "climax" of content for the run of Cataclysm.
“4.3 is definitely the climax of Cataclysm, so there’s no more Cataclysm content,” said Kosak.

“Traditionally we’ve had a grace period where we patch the game before the expansion comes out and you get sort of mechanical changes before you get the new expansion content. So we’ll have a world event prior to Mists of Pandaria, but that’s mostly a part of Mists of Pandaria’s launch and it’s not really more Cataclysm content.”
No date has been announced for Mists of Pandaria.