Kinect was originally able to detect fingers but it's been removed since. I'm guessing because it takes a little more horsepower to do so and would add some more lag or there were other technical diffiiculties that they didn't have time to get around.
Well, here's a video showing a Minority Report like interface with Kinect and the developer has created a package to detect all the fingers in a hand to give you control over a UI. It's a pretty slick video and shows off some some interesting possibilities. Now, could it be detecting the fingers and sacrificing the rest of the body as the resulting video only shows the points on the fingers. Don't know, but still a fun video to check out and see what some people can do with the Kinect camera now.