During the Microsoft E3 press conference, Microsoft announced four brand new exclusive Xbox Live Arcade games. First comes the sequel to the first true great Live Arcade game Geometry Wars, being developed by the original developers Bizarre Creations, Geometry Wars 2.

Portal: Still Alive was announced as an exclusive for Live Arcade, coming this fall. For the first time in 20 years, Galaga will be getting a true sequel in the form of Galaga Legion, and the same team who developed Pac-Man: Championship Edition are doing the honors. Finally, there was the announcement of a South Park videogame for 2009, although details were few.

It’s gonna be a busy few months for Xbox Live, with a revamped UI coming down the pipe, an expanded video marketplace, and a bunch of new games.