Microsoft earlier today announced a new product called "Microsoft Surface". If you haven't checked out the online videos of it yet, I highly recommend watching them here. It is one of those products that looks and feels like it comes from a science fiction movie - but it is actually real.
Popular Mechanics also has a good article (including their own video) of how it works that you can read and watch online here.
One of the really cool things about Microsoft Surface is that the table UI experience is built entirely using WPF and the .NET Framework - which is a great statement about the power of what WPF provides.
If you are interested in learning more about programming WPF, there are two great books out there that I've been recommending to people:
Both books have 5 star ratings on Amazon.com. You can download the first chapter of Chris' book for free from this web page.
Hope this helps,