Very cool, I like the new format (again). I'm not sure why you are having a hard time getting people to participate in this thread, hopefully your game of the day idea will help with that.
On that topic, I think Forza 2's sales were certainly greatly helped by the bundle with the game. Still I think it wasn't bundled until after it had passed Forza's sells, and maybe was getting close to 2 million. It seems like there is starting to be a lot of hype for the game, so I think that if GT 5 does not release until next year,that your right it could take away from GT 5's steam. I think some people might be impatient to play a great racing sim, and instead of waiting for GT 5 they will go ahead and pick up Forza 3, and by the time GT 5 comes out, they won't feel the need to pick that game up as well. Although of GT 5 will still sell very well.