It will have huge initial sales, but not THAT long legs, as most buyers are buying it right when it hits the market, especially in the US.
2-3m the first 3 weeks, 4m lifetime

1.2m first week, and about 5m lifetime. Seeing as most 360 games dont have the best legs it will reach 5m fairly fast then drop right off.

2m first week, 7-8 million lifetime. :) Here is a game that I am waiting for. :D

GeOW 2 has a good time frame for being out. The x360 momentum should be picking up a bit around that time, i think the sales for the game are going to nearing 2.5-3mil range.

It should keep selling well untill around xmas time

Somewhere near what cod4 did, most probably. +/-10%

i think microsoft will have a price cut so im guessing 1.8 million in the us first week and .6 million in others

1.5 million WW first week. Around 4-5 million LTD WW.

thinking about anything under 7M LTD is foolish...when GOW came out there were less than 7M x360's owners and still the game managed to break the 5M barrier.
GOW2 will be launched on the back of a 20M+ userbase. I wouldn't be surprised if the game sells better than Halo 3 (LTD).

2,5M first week and 9M LTD.

Its going up against Resistance 2! I predict NO sales!

With the current userbase and its tendency towards FPS plus the hype that it's generating even amoung friends of mine who didn't buy the first installment, I'm going to put first week sales in the 2.5m region.