Silverlight Beta 2 was made available late last week which means that anyone who has written samples or projects with Beta 1 has a bit of work to do. Upgrading my Silverlight Surface sample was pain-free, but that was because the code was fairly simple.
One of the changes made to Beta 2 was the further separation of the Silverlight assemblies. The System.Net assembly now contains the WebClient class (previously in System.Windows) and due to a few other changes, it is often the case that a reference to System.Windows.Controls.Extended is no longer required. This reduces the size of your .xap file quite considerably, and so traffic and download times. The Silverlight Surface .xap went from 199Kb down to 70Kb!
TheADOGuy has a blog post which gives a pretty comprehensive list of what to look for when migrating a project.
