Is MEF a dependency injection framework?

Question

The recently announced managed extensibility framework (MEF) of .NET 4.0 - is it a dependency injection framework? Will Microsoft Unity from Patterns and Practices be obsole

Answer 1

I saw one write up that made it sound like one but more information (Scott Guthrie at PDC2008[Video/wmv]) made me think it's more than a dependency injection framework. From the sounds of things it can be used for dependency injection but also does more.