Well, of course the idea of doing an application that uses this technology (group of existing technologies actually) has been intriguing to me, but I haven't the time or energy to work out how to implement it in our environment here at work. We are a Microsoft shop working mostly in C# but also doing some VB.NET stuff. Then I came across AJAX.NET. Looking at the documentation, this is going to make it so easy to do a proof of concept. If you have to do a lot of web user interface, check out AJAX.NET, while it isn't a perfect solution to the web user interface problem, it's definitely a step in the right direction.