Big changes in the Silverlight roadmap
Silverlight 2.0 will actually look more like Flex. The most interesting thing is that they're going to bring more of WPF's UI framework into Silverlight. This will be stuff like extensible controls, the layout manager and data binding in addition to all of the skinning and templating that WPF has. It should make the Blend WPF/Silverlight experience a lot more seamless.
In addition, they've overhauled some of the technical aspects in Silverlight 2.0. The rich control set is aimed at giving you the ability to create actual applications and they are going to have a high level of networking support. Scott's blog says you'll be able to expect REST, POX, RSS and Web Services from Silverlight. This brings it up to par in a lot of ways with Flash on the networking side.
Expect tools to go with Visual Studio around the beta time. Regardless of whether the beta hits before or at MIX, it will be an interesting conference. Scott said there are things they aren't announcing/talking about yet so I think Silverlight 2.0 is going to be a pretty significant release.
Update: Tim Sneath has some good info about how Silverlight 2.0 will bring the UI side much closer to WPF. Worth reading.