One of the cooler pieces of Silverlight 2 is the Deep Zoom Composer which allows an easy way to display high-resolution images. The ubiquitous Hard Rock Memorabilia site is an excellent example of its use. As its adoption grows, other, more interesting, applications have been developed. One really good one is Zoomery, which is using the technology as a code visualizer. The ability to quickly scan through the class diagrams and embedding notes directly within them is brilliant.
Oftentimes, Silverlight gets a bad rap as a Flash clone but this innovation illustrates (quite literally) it can be very original as well. I hope it continues to get Microsoft and third-party development and support.