Scott Guthrie announced yesterday that Silverlight 2 has been released. Rather than reposting everything he stated, you can read his original post here. Here are a few links to note:
Hope this helps to get you started using Silverlight 2.
Finally, I always wondered what their reach was with Silverlight. According to their press release, 1 out of every 4 already has Silverlight installed: http://www.microsoft.com/presspass/press/2008/oct08/10-13Silverlight2PR.mspx