According to a Blizzard slideshow presentation on their 2011 Q4 financial results, they reveal on page 18 that they will be aiming for a Q2 launch for Diablo 3, the latest game in the Diablo franchise. The same slide also reveals that more information will be out for World of Warcraft: Mists of Pandaria on March 19th. Mists of Pandaria will be the 4th expansion pack and will feature the new continent of Pandaria, a raise in the level cap from 85 to 90, as well as new game features.
There will be no Blizzcon this year as there will not be a lot of new information to announce with 1 game and 2 expansions already set to release this year.