This is nice. I recently saw something similar I liked with the heroku gem, where it forced me to upgrade to the latest version when I tried to use it, and outputted the gem update command.

[~] sudo update_rubygems
Installing RubyGems 1.3.5
RubyGems 1.3.5 installed

=== 1.3.5 / 2009-07-21

Bug fixes:

* Fix use of prerelease gems.
* Gem.bin_path no longer escapes path with spaces. Bug #25935 and #26458.

Deprecation Notices:

* Bulk index update is no longer supported (the code currently remains, but not
  the tests)
* Gem::manage_gems was removed in 1.3.3.
* Time::today was removed in 1.3.3.