PDC is approaching rapidly and Microsoft is opening up its communication around the next wave of technologies; one thing I believe to be particularly interesting is Codename Dublin.
This technology supplements Windows with much needed application platform components to enhance the WCF and WF design experience. Among other things it includes infrastructure services for message correlation and forwarding, content-based routing and transaction compensation.
I guess you can look at WCF and WF as frameworks and Dublin as infrastructure services around those frameworks.
The Dublin release will follow the release of .Net Framework v4.0 and Visual Studio 2010.