We are looking at switching from using WCF for our service layer in applications to REST.
So far we are assuming that the way to do this is to use the WCF REST Start
So far we are assuming that the way to do this is to use the WCF REST Starter Kit. However this is still in Preview 2 and hasn't been updated since March 2009.
You can build REST apps with WCF, without the Starter Kit. WCF that shipped in .NET 3.5 included good REST capability and tools. It includes the URI Template mapping, the WebGet attribute, and more.
The starter kit is sample code, add-on utility classes, videos, and other add-on stuff that helps illustrate how to do REST in WCF. You don't need the starter kit to do REST in WCF.
You do not need to wait for the starter kit to be "completed" in order to do REST in WCF. If there is stuff in there that you like, like the Http Request builder, then use it. It's open source, you can use in in your project. If you don't like it, don't use it.