I'll buy it if there is an offer for the game like there usually is for COD games on launch day - ie about £27 instead of it's usual £40.
I'll buy it since my friends will and COD games keep their value very well either way, so I won't lose any money on it either way, I think I ended up making some money on selling MW2 3-4 months after launch :L
Disconnect and self destruct, one bullet a time.