The WinFX November CTP was released this morning. Most notably, this is the first version of WinFX that runs against the final .NET Framework 2.0 bits. This means that you can now build WinFX applications using the RTM version of Visual Studio 2005, including the freely available Express Editions. To get going:
It's also useful to review the "Readme" file for this release.
Karsten's post includes a link to a draft version of an MSDN article that he wrote that explains the new features and changes in the November CTP. He also points to some downloadable code samples that include a handy tool for helping fix the mini-language changes. While you're at it, check out Kevin Moore's demo, and Tom Archer's post addresses some good Vista questions.