Jarek has written a blog and a sample of integrating caches into EF. One integration sample is using Velocity CTP3 bits. Take a look at http://blogs.msdn.com/jkowalski/archive/2009/06/11/tracing-and-caching-in-entity-framework-available-on-msdn-code-gallery.aspx

Sample code at http://code.msdn.microsoft.com/EFProviderWrappers