Oh, man. I've wanted Left 4 Dead 2 badly for so long and now it's on sale! Unfortunately I live in Australia, so I'd be stuck with the 'low violence' version. Maybe I can find a way to move overseas within the next day.
I read on the Steam forums, yesterday, for L4D2 that there are some options you can use when running the game to give you the uncensored version, in Australia. It's probably still on the first page of the forums.