Hi all,
  Introducing one9, a commandline tool to make the upgrade to 1.9.2
easier. It works by spying on
your tests and detecting 1.9 changes. Once your test suite finishes,
one9 prints a report listing
the exact locations of methods that have changed in 1.9.

Source: http://github.com/cldwalker/one9
Intro blog post: http://tagaholic.me/2011/03/05/one9-upgrade-to-ruby-19-now.html

I'm curious to hear what is stopping us from upgrading our jobs to
1.9.2. What other tools like one9 could help with this?
Thoughts?

Gabriel