We've uploaded a new version of the Desert gem on to RubyForge. This fixes the issues with template loading in Rails 2.1.0 and later.
From the changelog:
- Fixed exception in testspec.rake when rspec is not loaded
- Fix template loading on Edge Rails and on Rails 2.1.0
The Desert source is available on GitHub here.
The Gem is on RubyForge here.

For the moment, we don't see this new version of the gem listed when we run
So, you'll likely need to download it and install it manually until we figure out why it hasn't propagated.
If you happen to have thoughts on why it hasn't propagated, please feel free to speak up.
@adam
I suspect it is due to the incorrect rubyforge_project in the gemspec: