I plan on getting one soon, they're cheaper than most controllers and I get a few gifts to give to a friend or two. The idea seems wonderful and I've heard good things. It'll be great to be able to play from my bed without a cumbersome mouse and keyboard, still won't be as good of course. But much more accurate than thumbsticks. I'll tell you guys how it feels whenever I get one, and anyone who has/is getting one should give out their thoughts as well. =)
I have one pre-ordered. Only because it came with Rocket League which I was planning on buying anyway. It's not here yet though.
I'm not convinced that the trackpads will be better than sticks for movement in games. I'm guessing they'll be similar to the circle pads on the psp/3ds in terms of use. Better than nothing but not as good as a stick. Let me know how that works out. The 3DS is actually a pretty good controller for the PC. There's a homebrew app that lets you use the bottom touch screen to control the mouse, and it scales to the screen as opposed to just acting as a track pad. It's great for things like internet browsing/netflix searching on top of just acting like a controller for games.