At last week's Rails Conf, it was announced that the Rails 3.1 Release Candidate is ready to go, with 3 new features and a slew of improvements.
The 3 features:
The Asset Pipeline
For a full tour of this feature, have a look at the David Heinemeier Hansson keynote (58:00 total).
jQuery Is The Default
Rails 3.1: Release Candidate can be installed with with gem install rails --pre. The final version should be available in a couple of weeks.
[via RubyOnRails Blog]