Saw this over at the MSDN; great read on ASP.Net 2.0!
ASP.NET 2.0 Internals
Jayesh Patel, Bryan Acker, Robert McGovern
Microsoft ASP.NET 2.0
Summary: While 100 percent backward compatible with ASP.NET 1.1, ASP.NET 2.0 brings a number of internal changes to ASP.NET. These include changes to the code model, compilation, page lifecycle, and more. This article outlines those changes. (21 printed pages)