Yesterday it was announced this exciting release for Silverlight, since it provides a ton of new features, including built in controls, layout containers like Grid and StackPanel, control skinning, templating, improved networking, and better performance. It also provides better Visual Studio 2008 integration, and a new drop of Blend which supports the new controls.
You can download the Beta and the tools here.
So, what's the best way to start to get familiar with Silverlight 2? You can try Microsoft hands-on lab, after that you can check additional labs and tutorials on Silverlight site.