I've started an attempt to get the various ASP.NET teams either blogging or (for me) ideally writing for MSDN about their favourite features in ASP.NET 2.0. There has been a lot written about the "Big features", but I think people are (or should be) also interested in the smaller refinements. Mike Pope has a great blog post on the changes to the controls on the "Web Controls" tab of the control palette.

And I *still* think the Substitution control is just a whacky (but incredibly neat) idea.