Check out Steve Martin's post around  Microsoft .NET Framework 4.0 and “Dublin” Announcement

WCF  4.0 Enhancements - RESTful Singleton and collection support, ATOM feed and publishing support,  POX support over HTTP.  A unified XAML model that will let you create new apps just with XAML  from presentation, data, services and even workflow - no code folks!! A decorative model is in the works here as well

For WF 4.0 a 10 fold improvement in performance and scalability is targeted - more pre-built activities around Powershell and messaging etc.

Dublin will consist of next set of capabilities for the next generation app server which will extend IIS to provide a standard host for both WF and WCF services. Keep reading Steve Martins posts for more info...

Life, Liberty and the Pursuit of Simple Middleware - Steven Martin, CSD Product Management