As much as the Wii is a Fad. IMO I didn't understand the popularity of the Wii. We bought one because "we just had to" and my kids played it for a bit, now it is a piece of furniture. Standing in front of your big screen for ~how much time~ vs. sitting has it's pros but mostly cons. Once the novelty has worn off... but look at the sales numbers for the Wii. Should be the same for kinect, I don't see the difference other than there might be more technical diversity with the Kinect.
IMO, the Wii is a novelty item not a gaming platform. I can bowl for about 10 mintues as the system interprets my 5 year old's spastic movements as continuous strikes while I constantly get splits. Versus 60+ hours of fun at Mass Effect.
Its a good product. I am impressed by the pc hacks. I think Microsoft should run with it and mass produce the product for pcs and macs. They could possibly charge a premium for it.
You're right, the wii is gimmicky and a surprising success. Although it had a lot going for it at the time, Nintendo fanboy support, very cheap price, timing.
I just don't see the Kinect revolutionizing the XBox besides the initial Kinect sales. Its not cheap and to get both the console and the kinect its worse. Gimmiky products cater to the casual gamer, and casual gamers don't buy many games besides the initial purchase. XBox has fairly loyal hardcore base that spends lots of money on many titles. Thats who developers will cater to. Also, you can make xbox games without any kinect support but it would be hard to get a game by Nintendo Q&A that had little if any wiimote support. So I don't see developers working very hard to have Kinect support unless the game specifically takes advantage of it. In the end its games that sell a platform, and on the Wii, wiimote support is basically a requirement to get on the platform.
To be frank I don't think it will get much more penetration than the PS3 eyetoy, although its a better product. This is all my opinion.