i think bioshocks initial sales will far overshadow MP3's, the 360 market is basically a 10 million strong fanbase of techno driven FPS fans, the Wii market is a 10million strong fanbase of casual/party/mario game fans.

I think MP3's sales will overall beat BS's, but that will be because no other FPS will match it for a long time, the 360 has Halo3 very soon.

Bioshock - Larger install base (but also a PC release so some cannibalization will occur), been out a whole week so should sell more in the first week than MP3

Metroid - Smaller install base not out a whole week, should sell less the first week than BS

I'm going to go against the tide here and say that Bioshock will have higher first week sales. 360 users flock to a game on day one. The Wii isn't owned by those who want the latest in FPS games. It's owned by those who want Wii Play and Mario Party 8. (Yes, there may be some overlap with the Metroid crowd, but not as much as you'd like to think.) And the games for the system seem to have more of a flat sales curve. So for the first week of each:

Bioshock - 500K

MP3: Corruption - 300K

Bioshock will sell around 600k and MP3 will sell around 300k both are great and should have long legs to sell well thru the holidays. I think both will sell over 1.5m by the end of the year.

I guess Bioshock will have stronger initial sales than MP3, mostly because large part of Xbox360 audience is FPS orientated. That said, i'm pretty sure that MP3 will win in the long run, as it will be a good reason for GC owners to switch to Wii, and make FPS lovers to buy Wii as the second console or PC-Wii combination (due to controls).

Also, MP3 will sell better than Bioshock(X360 ver) in Europe, because FPS players there are mostly PC orientated, so PC ver of Bioshock will be their first choice.

MP3 ... by a longshot. 90% of xbox360 games are shooters, therefore there's no rush to buy Bioshock brand new. Some will buy (or rent) it (beat it and sale it in 2-3 days) and others will wait till its used. 360 is saturated with shooters which will shorten the life of this game. Plus, its too close to Halo 3 (the reason 90% bought 360) release

MP3....315,000
Bioshock... 180,000

I guest the closest!

A large part of the x360 is fps overrated?

Best x360 games

bioshock(fps)
halo series(fps)
gears of war(3rd person same crud just with his head out)

More than 80% of x360 owners will buy this game. Because its a great fps.

after seeing Bioshocks first week sales there's no way i can predict MP8 to outsell it.

 Yeah Mario Party 8 only did 309k or so.

But MP3 might have a chance still, I wouldn't discount it yet but it has its work cut out for it.