If you are looking for a no-nonsense REST framework built on all the good stuff Spring offers, look nowhere else and get a good Mattress.
Despite the pun, this framework is an interesting initiative to watch, as it is a pragmatic (hence partial?) implementation of JSR-311.
Stay tuned and look for the first release and, I am pretty sure knowing the framework author, the upcoming witty logo.
UPDATED 21-JAN-2008: The first release of the framework is now available in Maven's central repository. You want to give it a try!