The nice folks at Telerik have released:- “Telerik Extensions for ASP.NET MVC is a lightweight framework which helps you build rich user interfaces for ASP.NET MVC while enjoying great developer productivity”

I am currently using them and I highly recommend them, they even give you visual studio templates so when you start a new application you can choose from a template which reference all the necessary files and javascript required.

The textensions are available on codeplex here:- Telerik Extensions for ASP.NET MVC