Ruby Plugin 2.0 Features
RubyMine — is the dedicated Ruby & Ruby on Rails IDE based on IntelliJ IDEA and with similar functionality as the Ruby Plugin. Official Site.
RubyMine Early Access Program (Updated Mar 6)
1.0 Beta Todo
Since version 2.0, the plugin is no longer open source.
You can download plugin builds, comment and rate the plugin in the Plugin Repository.