I've just released uBase - a new extension for Umbraco.
uBase is the evolution of the Umbraco /base framework, and is based on ASP.NET WebAPI.
The package lets you create REST api's running side-by-side with Umbraco and you can also protect your api's based on the currently logged on Member or backend User.
You can also protect by Member group and even Member Type or User Type!
All this can be specified for the entire service, or individual functions.
You can install it as a NuGet package or as a Umbraco Package. Right now they are one and the same, but in the future the Umbraco package will include some awesome built-in api's.
Isn't this just like uRest?
Not at all. uRest provides access to content and other stuff stored Umbraco via a REST interface.
uBase is a framework you can use to create your own services and protect them based on Umbraco Member and User info.
That said, uRest will definately get some WebAPI love in the future. :-)