Even though Silverlight 3 and Expression Blend 3 + SketchFlow RC (not final), are already available for download since yesterday, Silverlight 3 and Expression 3 will be unveiled at a virtual launch event today!
Currently if you go to http://www.seethelight.com/ you will see a countdown timer, so it’s easy to determine when to come back for the virtual launch. This countdown timer can also be seen on the Expression site.
Silverlight 3 has quite a few new features and updates, check out this guide by Tim Heuer. Also note that a Silverlight 2 project opened in Blend 3 will ask to be automatically updated to Silverlight 3. This cannot be undone. Expression Encoder 3 will also be part of the Expression 3/Silverlight 3 launch. There are many exciting new features in this release – check out the detailed posting on the Expression Encoder Team Blog.