Kinect has sold incredibly well and I believe it'll exceed Microsoft's goal of $5 million units after holiday. Microsoft has announced it sold 2.5 million Kinect in one month. Also best news is that Microsoft said they plan to upgrade current Kinect to take advantage of high resolution camera (originally it was thought Kinect uses 320x240 but it's actually is 640x480! If you hook Kinect up on PC, you'll see two 640x480 images) so it's easily upgradable via firmware.
I think Kinect will be something developers will pay attention to in the near future.