@ x-M-x
No you won't be able to play until thuesday , developers aren't idiots.. just like with MW2 launch they probably have files that arent on the disc, you'll need to download them from the steam service in order to activate the game and even get it running.
Retailers sometimes get the games a whole week before the date, just because they've them in stock doesn't mean it will go out before the date , jeez ffs grow some brain?