33 of my friends (out of 100) are online on XBox Live right now. Of those 33, only 8 are not playing Halo 2. ie: 25% of the people on my friends list are playing Halo. Usually I might see 5-10 people online at any time, most of them playing Project Gotham Racing 2 (since that's what I play most).

UVic was kind enough to suspend school for the next 3 days so we could get Halo 2 out of our systems. (As if 3 days is enough)