This is good news for those of us that frequently use Ruby's win32ole module to automate Excel, Word, and a variety of other Windows applications and processes. Now you have the option of running your code on the JVM.
And running on the JVM opens up a world of possibilities. You could, for example, whip up a Swing GUI via Monkeybars, and use Rawr to package it up as an EXE file for ease of distribution.
Interested? Download JRuby 1.6 at jruby.org, take the win32ole module for a drive around the block, and let me know if you hit any potholes.