One of the issues I have with ASP.NET is that it is postback crazy. Virtually nothing of significance can be done in pure browser client code with ASP.NET out of the box*. You have to Submit() the specially formed ASP.NET HTML form to the server, and all the event magic happens server side.
This is a companion discussion topic for the original blog entry at: http://www.codinghorror.com/blog/2004/10/the-antidote-to-aspnet-smart-navigation.html