March 12, 2013.
The beta for Starcraft 2: Heart of the Swarm has recently been released.
sometime in your life
Buy it when it comes out next year (or longer)
Yes, Heart of the Swarm is considered an Expansion pack and therefore it requires the base game of Starcraft 2: Wings of Liberty.
There is no release date yet, but the summer of 2012 is most likely.
I'm not sure what you are talking about because Starcraft 2 is released already. But it was released July 27, 2010. This is only counting Wings of Liberty because no one knows when Heart of the Swarm or Legacy of the Void will come out (my guess is that Heart of the Swarm will come out 2012-1013 and Legacy of the Void will come out in 2014-1015).
No because you're only playing as kerrigan working w/ zerg.
I don't remember off the top of my head, but it is in either February or march 2013. I cant wait!
Blizzard Entertainment has not announced a date yet.
The game will be split into three separate products, based around the terran, zerg and protoss campaigns respectively. The first is called StarCraft II: Wings of Liberty, the second will be called StarCraft II: Heart of the Swarm and the third will be called StarCraft II: Legacy of the Void. So if by Starcraft 2 you mean Starcraft 2: Wings of Liberty then yes only terran but there will be three game products for the zerg and protoss campaigns.
For now, the campaign has only Terran and (a small number of) Protoss missions. In "Heart of the Swarm" there will be Zerg missions.
starcraft 2 Wings Of Liberty has already come out, but the other expansions haven't come out, unfortunately...