This is a great start, but I'd like to see them backport the KB/Mouse to their older games as well.
I've always been a PC gamer, but this is step in the right direction. They could port it to Portal 2 with a Software patch, and I'd be a happy guy.
If more companies did this, the PS3 would be an obvious buy for me..
I also like the openness Sony's had with their PSN, and I like that I can buy Portal 2 for PS3, and get a Steam version for free.
Sony is a bunch of asshats in lots of areas, but they're doing OK on this part.
I GREATLY prefer to buy games through Steam, and will often pay a premium to do so. It gives me the convenience of being able to download it on any PC I go to; It's in my list, along with every other game.
I don't need to store the DMG or ISO, and go through a manual install process. It's all there, in one place, easy as pie, and ready to move across systems.
Somebody ought to cross ball point pens with coat hangers so that the pens will multiply instead of disappear.