I'm in the same boat as you Alias. I won't even consider a game unless it has XBL features.
Notable exceptions for the future however, include:
Halo 2 (even if they scrapped the Live section right now, I'm there on the first day)
KOTOR (The anticipation got the better of me on this one)
Half Life 2 (I know its live enabled, but even so, they say it looks better on XB than on PC)
Fable (I'll consider anything)
And a few others.......
Now for sports game......totally unacceptable. Madden is out this year....at least as my MAIN FOOTBALL TITLE.