I think as far as the 360 version of it goes, the novelty will wear out very quickly. I think the tech has room to grow in the future and can see it become a part of your daily life, replacing remotes for example...
That being said, I don't think it has the price point and a strong enough appeal to really entice casual gamers to take the plunge and buy a 360 AND Kinect AND full priced games for it when they can get a Wii for cheaper with already successful and recognized franchises. I think the tech is neat, in concept, but I worry about its execution at this point in time. The Launch line-up is not offering anything that feels entirely new, Everything is Mii-too.
We'll see what the future holds, but so far, I don't think it will have such a big impact.
When the Wii got out, casual AND hardcore gamers were in awe before its incredible potential. Even if it did not fully live up to those expectations (except for the first party titles and a few other exceptions) the fact remains that the buzz was strong when it launched.
In the case of Kinect, the buzz is not nearly as strong, and it's in part due to MS basically saying: "Screw you, old time fans, we're going after an other market" by offering no serious games for the core and hardcore gamers. In fact, the only thing I can see that it offers for old time 360 users are the interface functionalities. Those are good, yeah, but hardly worth its price tag.
To be more specific to the topic here while still taking what I've already said into consideration, the fact that they staged a lot of their stuff during their presentation, and how the reports from every gaming sites mention multiple problems with the device like lag, 2 players only for full body recognition gameplay (could still handle more for simpler game types), no sitting (even if they're supposed to fix that), along with what I mentioned earlier (lack of core experiences) is definitely hurting how I view the device at this point. So, as far as I'm concerned, this device is certainly not trying to be sold to me, an avid gamer.
