I demo'd a touch screen with Windows 8 at Sam's Club over the weekend and I have to say, it was much easier to navigate with it. My primary development machine is running Win8 with no touch screen and with a mouse it just needs some work. I can do everything I need to but it seems to take a few more clicks (I get stuck in the Metro App/Start Screen/Desktop triangle where I'm trying to get to the desktop but my uncoordinated brain somehow keeps switching between the last metro app used and the start screen). I also find the charms bar irritating on a 2nd monitor where if you slide too far to the left it will disappear causing you to have to go hover back down in the corner to get it to come up again.
Obviously, I get it done, it's just more frustrating. That's me, I understand others like it. What Microsoft should have done was make everyone happy and provide some options in setup. Had they done that, they could have kept the good press they were getting going.
Back to your question, would a sight like that be useful? Sure, but only if it was popular enough to garner someone from Microsoft (who can make decisions) to take it seriously. My feel is that Microsoft will only react when they don't see the adoption rates they want (like, if most enterprises don't adopt it, which mine isn't and won't with the exception of a few tablets that will make their way in).