I don't see buyers remorse setting in for me with Kinect for two big reasons.
1. I have enough space to leave Kinect set up and it not be a hassle to get it up and running.
2. I am using the device mainly as a workout aid.
I have been wanting to get in better shape for a long time. Wii Fit was too much hassle, and the board felt flimsy. The controller didn't feel responsive at all and I hated how obvious it was that I could cheat the game by just flicking my wrists rather than actually work out.
Yourself Fitness is providing great motivation to keep working out, and doesn't feel as punitive as Wii Fit did at times. I am also eating better. So, Kinect is a part of a lifestyle change for myself and my wife. Moving with Kinect is much more of a full body activity than playing with the Move or Wii remotes. While I think those two have some fine (even great) applications, they have not become a part of my everyday life like Kinect has in such a short time.
I don't think Kinect is perfect by any means, and I definitely don't think my situation applies to a wide swath of gamers, but so far I am very happy with it.