The Whidbey provider pattern was the tip of iceberg
Note: this entry has moved.
I have complained in the past about the shortcomings of the Whidbey provider pattern (ASP.NET should I say?), which I always regarded as woefully inadecuate as a general purpose pattern for complex blocks and pluggable providers. At ClariuS it's not our style to just complain, so we got one of our brightest brains to work on Enterprise Library and do something about it. The result is amazing: both simple yet incredible powerful and flexible. I would bet you will see his code in VS Orcas! Don't miss his first post explaining what it's all about.