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.
Life is cheap, but the accessories can kill you.