If you haven't seen all the video clips for Microsoft Surface yet you'll have to check them out. Surface should be really cool and should enable some giant steps forward with user interfaces. Your typical windowed application will be a thing of the past and that should also carry over into desktop computers. I'd expect some multi-touch flat panels for your PC too.
From what I've read, all the apps shown on Surface were written using WPF on the .Net Framework. Silverlight is another technology from Microsoft that brings WPF and .Net to the web browser (cross-platform even). Silverlight is the re-branded WPF/E code and is the next big thing from MS as far as the visual web goes. We used Silverlight (then WPF/E) for a SalesWorks demo back in February. Think of Silverlight as Microsoft's version of Flash.
To see something really neat, check out this demo of a Surface-style app using Silverlight in your web browser. You'll need to install the Silverlight Alpha to see it (just click thru the steps to install it). Yeah, that's a video file running in there. It's really amazing. You just want to put your fingers to the screen and start dragging the pictures around.