Please take a look at the new MSDN site serving as the single content point for current ASP.NET customers to easily make the move to ASP.NET 2.0.
Upgrade Center: http://msdn.microsoft.com/asp.net/migration/upgrade/default.aspx
Also, check out the new whitepaper that details the lessons learned, best practices, and valuable techniques that will help developers upgrade their apps.
New Upgrade Paper: http://msdn.microsoft.com/asp.net/default.aspx?pull=/library/en-us/dnaspp/html/upgradingaspnet.asp
For general migration (ASP, competitive, etc.) content, you can always refer to our migration center at: http://msdn.microsoft.com/asp.net/migration/