COD 6 multilayer is free for the weekend, pre loading has started.
Supposed to be amazing on the consoles.
link to Install (hopefully)
If you are in the new GUI beta it seems to download it in the background.
Go to your steam apps folder / common, and you will see
call of duty modern warfare 2. It's getting larger by the minuet.
It's now open, roughly till Monday, but who knows.