Mike Morhaime yesterday announced at the Activision Blizzard pre-E3 conference, that the release of the highly anticipated StarCraft 2 is planned for this year:
We're targeting an end of year release, this year, for StarCraft 2, but as always, we won't release it until it meets our standards and the expectations of our players.
The first episode of the StarCraft 2 trilogy will be Terrans: Wings of Liberty. It will contain the "human race" single player, and a full multiplayer including all three races. Last month the Blizzard staff created a thread on the official Battle.Net forum with informations on how to participate in the StarCraft 2 (Diablo and WarCraft Universe as well) beta test. You will need at least one original Blizzard game key to proceed. Of course registration won't give you a sure ticket to participate in the beta.

Source: shacknews