This TMBundle works with both rspec-1 and rspec-2. Given that they work differently, the TMBundle tries its best to figure out which one you're using in each project.
If you're using Bundler in your project, the TMBundle will always do the right thing based on the version of RSpec specified in your Gemfile.
If you're not using Bundler, the TMBundle tries to do the right thing based the presence of assorted files and paths in your project. Obviously, everybody's environment is going to be a bit different, so let us know if this doesn't work for you by filing an issue at http://github.com/rspec/rspec-tmbundle and we'll do our best to resolve the situation.
cd ~/Library/Application\ Support/TextMate/Bundles/
git clone git://github.com/rspec/rspec-tmbundle.git RSpec.tmbundle
osascript -e 'tell app "TextMate" to reload bundles'
Parts of RSpec.tmbundle is based on Florian Weber's TDDMate.
The license of RSpec.tmbundle is the same as RSpec's.