The best news about this release is the Ruby Browsing perspective. Then there is the New Class wizard and
improvements on template handling and syntax highlighting. The complete Changelog: http://download.rubypeople.org/nightly/Changelog.txt
RDT 0.8.0 runs with Eclipse 3.1 and 3.2 (tested with RC1a).
for instructions on installing either the zip file or via update manager.