There's five co-op releases this week, highlighted by the monster that is Borderlands. On the opposite end of the spectrum we have two family friendly titles and a karaoke game that's sure to make anyone's next party a blast. All the games release today and are available from Amazon.
Borderlands on the Xbox 360 and PlayStation 3 features 4 player online co-op with drop in and drop out support, as well as 2 player local co-op.
Lips #1 Hits on the Xbox 360 features 2 player local co-op for duet singing in special songs, as well as alternating singing in all songs. There's even co-op specific leaderboards.
Marvel Super Hero Squad is the kid friendly answer to Ultimate Alliance 2 on the Wii and PS2. The action game boasts over 200 playable characters from the Marvel universe with 2 player local co-op. Take that DLC!
Astro Boy is the game based on the movie based on the cartoon. It supports two player local co-op through the game's single player mode and is out on the PS2 and the Wii.
Also the PSP version of Grand Theft Auto: Chinatown Wars releases today with it's survival co-op mode. It's got two player local wireless play, social aspects like items trading as well as brand new graphics.