ASP.NET and ADO.NET 2.0
I felt guilty about reading the outlines for these two books: A First Look at ASP.NET 2.0 and A First Look at ADO.NET and System.Xml v 2.0. Not guilty enough to not post it of course.
ADO.NET v 2.0 really doesn't get a lot of play. I'm pretty excited about seeing the changes and how it's going to integrate into Yukon.