i think you guys are really going to miss a lot of consumers not releasing on the 360.
while I own a ps3, 360, wii and PC, my pc is for work only. I had too many games crash my system and after upgrading my gaming rig for the umpteenth time for yet another new game / update I finally swore of PC gaming. I mean I spent like 10k over 3 years on new hardware / systems not counting the price for a separate rig for work and all the time lost tweaking each game or hardware to squeeze out the best FPS and PQ.
As much as I like sony games, multi console games on the 360 tend to be better so my PS3 is my blue ray player save for a few select games like uncharted, little big planet, etc. Dont get me wrong I like the system but the online component is meh.
The majority of my game time is dedicated to my 360 since everyone I know plays on it and I can always find active game rooms. I think you guys will be really missing a huge install base here and I would imagine, most gamers like myself, would opt for the 360 version (a fact that is backed by sales figures) if giving a choice between all platforms.
Let's face it and as your price suggest, BTTF is not going to be a Modern Warfare or Grand Theft Auto (in terms of size or re-playability) type of game. Most likely, BTTF will be a game I play in between games and since 98% of my time is spent on my 360, I'm not going to want to go through the hassle of changing systems mid play when I want a break from something else. I'd rather go to my downloads and select something.
even though I own all systems, a good PC and being a HUGE BTTF fan I'm not going to be playing BTTF unless it hits the 360. =(