Looking at an older stackoverflow post (back in June 2009, Is the WCF REST Starter Kit dead in the water?), a Microsoft employee said they were pretty close to releasing the next version of the Starter Kit. That was a looong time ago and... they haven't released one. So I'm asking again, Microsoft... is that kit dead in the water?
It will be part of .NET 4 / WCF 4 that should be released next time (April 12).
I haven't heard anything whether some or all of the improvement in WCF REST will be back-ported to run under .NET 3.5 - probably not.