The beta of the the Model View Controller (MVC) framework for ASP.NET was released today. Get ASP.NET MVC here

The beta version is very similar to Preview Release 5 but moves the DLLs into the GAC so you don't have to copy them to your local folder if you know MVC is installed on the server. If you're not sure you can always include the DLLs and the MVC framework will work on any web host that supports the .NET 3.5 framework. SP1 is not required anymore.

 I've been experimenting with the MVC framework and I really like parts of it. The controller architecture forces you to pass every that your HTML needs to render into the ViewData collection. At first this is kind of off putting and feels like an extra step. After a while it starts to grow on you and now I really like thinking about application logic first and then only sending the bare minimum data the page needs to render correctly. I think it forces you to be a frugal developer and will lead to better performing apps and easier updates down the road.

If you haven't tried it yet now is a good time. One note, MVC is NOT going to replace WebForms (the regular way to build ASP.NET apps). Microsoft has been very clear that they will be updating and supporting both WebForms and MVC going forward.