I was so worried about this, until I remember that Valve can really do no wrong in Yahtzee's eyes.
Regardless, I'm not surprised he liked the game. it's a good freaking game, and the tension it has continues, even if you know what's going to happen. Sure you know how to kill a smoker or a hunter, but you never know WHEN they're going to show up.
If Valve doesn't diss the 360, it's going to be fantastic. They'll add levels, and such. To be honest, I think Valve, while trying to make it fair for "us" screwed us all over by not releasing ANYTHING for Team Fortress. If they do the same with Left 4 Dead, then I want to personally wander down to their offices and tea bag each person.
WHO IS THE GUY IN THE PICTURE. it's getting on my nerves, now. Grr.