Mass Effect 2
Bioshock 2
Dead Space 2
Kayne & Lynch 2
Just Cause 2
Dead Rising 2
(Last two's originals were released in 2006, but 4th quarter)
Starcraft 2 (probably, though of course the original is far older than those of the above)

The list goes on and on. I found a full list of sequels slated for release in 2010 here:

http://gaming.hexus.net/content/item.php?item=21777

Craziness, like deja vu all over again