Welcome to The Escapist from me, too.
I've chosen 'other' since I don't really have much of an opinion on it (I haven't played it), as I'm one of the 17 people actually boycotting it; only IW. And right now, my opinion of IW isn't good. I'm a PC gamer, and CoD4 was pretty stellar, but they butchered the PC version. This does go beyond the usual "we want dedicated servers BAWWWWW" argument, however, since lag and cheaters are a big concern to me, since my internet is already bad as it is.
Seriously, if anyone besides me uses our Internet (family of 6, and my younger brother and sister use the Internet a lot...) even for browsing while I try and play a game, my ping can go over 2000. I wish I was kidding. P2P would only make that worse. Not to mention there's no real way to get rid of cheaters that join your game.
IW seems to think that IW.Net stops cheaters and pirates... I thought they new better thanks to CoD4, but apparently they're some of 'those' people that think hackers and pirates can be any more than delayed and inconvenienced.
I'll still get it though, but only if;
a) They release a patch to fix the PC version.
b) The price drops significantly. I am not paying full price for the damn thing as it is now.
Whichever comes first.