Some months ago Brad Severtson gave use some nice rich data examples using MVC 4 beta and Upshot.js, unfortunatelly the current asp.net roadmap put this in the fridge. Which kind of makes sense because there are already two big open-project doing something similar. The code is still available and I think their implementation of a DbController wrapper around the web.api is sweet and I am going to keep for the moment. As alternative to Upshot.js I will switch to Breeze, mainly because it is endorsed by John Papa. (and yes I know he is friends with Ward from Breeze). Edit: I am currently trying out JayData more, it seems more complete then Breezejs. Edit 2: it's now july 2013 and I am using Breezejs together with Angularjs in production for most of my mojoPortal sites.
The alternatives to Upshot.js
There are also some other small libraries, but I think they will disappear. (Data.js from the Asp.Net OData team, KnockoutSPA, SPA.js, ...)
Maybe you got here because of the following error (using upshot beta with the mvc4 rc does not work):
Method not found: 'Void System.Net.Http.Headers.HttpHeaders.AddWithoutValidation(System.String, System.Collections.Generic.IEnumerable`1<System.String>)'.