A work colleague recently turned me on to Microsoft's Managed Extensibility Framework (MEF) [see http://mef.codeplex.com/]. For anyone into Prism, MEF is worth a look. Headed up by Glenn Block of Prism fame, MEF is an impressive technology.
Glenn gives an hour long MEF presentation at PDC 09 at http://microsoftpdc.com/Sessions/FT24.
In addition to an MEF orientation, there is a short presentation on MEF + Prism.
Exciting stuff, in a geeky sort of way.