In his words, he set out to build a template for Windows Azure templates that:
In the post he shows how to take the RoleManger and expose it through MEF, thereby making it pluggable. He then creates a mock Role Manager for use in his unit tests, thus removing the dependency on all the Azure infrastructure.
I am guessing this is the first of many posts to come on MEF and Azure.
For more, check out Magnus post here.