I also work at M$ (contractor!) but not on Kinect and those demos were definitely legit. My office happens happens to be near where it's worked on, and I've playtested it briefly on several occasions. I think today's demo and the hype doesn't nearly do the platform justice - I've already gone to GameStop to (try to) pre-order...it's frikkin' amazing.

If you watch the video carefully, you'll notice there are are essentially two types of use of the platform:

1. Most games seem to have a delay between when you move and when that movement shows up on screen. These games are either ones where you notice something you have to react to, you react, and then you see something happen after a delay, or ones where you sorta 'pre-act' moves you know are coming. If you watch the video where they are avoiding things on the track, you can see them move their bodies early, anticipating that the game won't get the move in time if they jump in time with what they see.

2. The dance game seemed to do a kind of post-analysis to see if what you did is correct - I think this is very similar to existing singing games out there - you calibrate it so you can sing with the music as you hear it, but the scoring mechanism doesn't come back with how well you're doing as fast as you're doing it. I'm pretty sure they must be doing the same thing here - you dance to what you see, and the scoring chimes in a moment later with "yup, that last move was great" or whatever. If you look on the right side you can see the upcoming moves - that's how you know what to do next - also you can see yourself moving on the right in a small box - i think if you look there you'll see yourself delayed.

I play FPS games - 30 fps is fine as far as visual quality goes - sure, 60 fps is better, but I don't care - it's not the visual quality that concerns me.

What does concern me is the delay in getting the information I need when I'm playing.

Ideally, I'd like infinite FPS - then, when an opponent appears, I'd see it as soon as possible after the data makes it from the computer to the monitor. At 30 FPS, there is an additional delay, probably up to 33 ms, probably averaging 16 ms. At 60 FPS, that additional delay is cut in half, and at 120 FPS, it's cut in half again. In short, I get relevant information sooner, and that makes me play better.

Often battles in FPS games are literally two people who both shoot each other in the head for a one shot kill as soon as they see each other. Players want to minimize any delay so the game will decide they shot first, and win the encounter - every little ms matters, as any skilled gamer knows all too well.