MEF enables this extensibility to take place without creating a hard dependency in either direction. Applications can be extended at run time without recompilation, and extensions can be used by multiple applications sharing the same extension requirements. MEF also allows an application to delay the loading of an extension while still examining its metadata, enabling efficient traversal of large catalogs of extensions.
For more information, download the community technical preview (CTP) archive containing binaries, samples, and documentation!
One of the goals of the CTP is to get early feedback from the community. We'd love to hear from you - let us know what you think on the forum.
SITE:http://code.msdn.microsoft.com/mef