The baby? Guitar Hero III. The Shark? Rock Band.

In keeping with their promise to have new downloadable content once a week following the launch of Rock Band, Harmonix has revealed to GamePro magazine that Nirvana's 1991 album, Nevermind, will be one of the first fully playable albums made available following the previously announced Who's Next by The Who. It has also been implied that one or more unspecified Metallica albums will eventually be available as well.

All three bands are featured in the game's main tracklist so one need only look at the already announced tracks to get an idea of what other bands we may see get the full album treatment: Stone Temple Pilots, Blue Öyster Cult, Weezer, Foo Fighters, The Ramones. I may never leave the house again.

The most important piece of info is still at large, however: How many MS Points/PSN Virtual Dollars are these albums going to set us back? Using Activision's current Guitar Hero II pricing model of $6.25 for three random songs, the 12-track Nevermind would be $25. Kind of puts Activision's pricing into perspective, no? I'm hoping for something a little closer to $15.

Also just announced, and very cool, is the use of real rock venues, 41 to be exact, from all over the world. As someone who has seen a few hundred concerts in pretty much every venue in NYC, I can't wait to see what ends up in the game.

Oh, and Harmonix? If you could lock up The Smashing Pumpkins' Siamese Dream, that'd be great. 5000 Microsoft Points, you say? No problem.

[via Joystiq]