Microsoft have announced Microsoft Silverlight, our next generation, cross platform, cross browser runtime for building rich media experiences on the Web. Silverlight, formerly known as WPF/E is the beginning of the next generation of the web, empowering Great user experiences.
There's a great post with a lot of details on Tim Sneath's blog -- including 9 of the top 10 great things about Silverlight. The tenth one is forthcoming! 🙂
I'm in China right now, working on a Silverlight event, including some great stuff that we will be showing at MIX. I hope you can join us!