Picked it up last night right at midnight (CST). There's a GameStop and Wal-Mart within two minutes of each other down here. Drove by the GameStop and, I shit you not, people were tailgating while waiting for the store to open. There were close to 200 people in line. We promptly headed over to Wal-Mart and waited in line with like 20 other smart people. I was playing by 12:20. Played for about 75 minutes and enjoyed it. I'm going to reserve final judgment until I can get some more HC SD time, as I generally hate the early modes you can play when you first start. Only got two Search games in, but I'm optimistic. I like the increased level of custimization in classes. I also like the fact that you have to earn weapons upgrades instead of buying the perks/attachments with CoD points.
I saw a 2nd prestige, level 49 last night at 1:45a CST. He was American. Dude must have had the game for a week now. He sucked something awful for having such a big advantage over people coming in fresh to the game (ie, knowing maps, routes, gun leveling, etc). Tried to pawn off some bullshit that he leveled up using the 2hrs of dbl exp. Turd.
EDIT: I forgot just how much better I like the feel of IW games than Treyarch games. The movement seems much smoother.