Rico is one of the smartest guys on the CLR team and he is super, super passionate about performance.  He is looking at everyway possible to make managed code run faster...   He just posted a great whitepaper on how the GC works and how to get the best perf possible out of your managed code... worth a read!

We call Sonja the Queen of Interop around here... In this MSDN TV show she shows how COM clients can use managed code.