Windows Server AppFabric provides management, monitoring, and other component services for WCF services using .Net 4. The beta 2 release of AppFabric came out a few weeks ago using the release candidate of .Net 4. Now that the final version of .Net 4 is available, you can get a refreshed version of Windows Server AppFabric Beta 2. You should completely uninstall any preview releases of .Net 4 and AppFabric before installing the final version of .Net 4 and the updated AppFabric beta.
If you haven’t tried Windows Server AppFabric, then there are some new Channel 9 videos available that walk through the features in the AppFabric dashboard as an introduction.