At least according to InfoWorld:

Ruby on Rails 2.0, a planned upgrade to the open-source Web framework, will feature REST (Representational State Transfer) as its preferred choice for Web services, the developer of the framework, David Heinemeier Hansson, said at the RailsConf 2007 event in Portland on Friday.

It continues to amaze me to see REST and Rails covered in what I perceive to be mainstream media, but probably not for much longer.