I've been wanting to give it another test drive and see how the latest version compares, but for the life of me I couldn't make this one simple thing happen. I've got multiple projects in both Ruby and jRuby, so not being able to easily switch is a big big pain.
I got as far as the "build path" bits, but I couldn't make those dance the way I wanted so I gave up and went back to NetBeans 6.5. Which works perfectly, but I'm not a fan of the default directory structure. If you use the "files" view instead of "projects" you lose a lot of functionality. :/
EDIT: "why not post on the Aptana forums?"
Because I forgot my username and password. And you can't get your password without supplying your username for some fucked up reason. So, basically I'm locked out of the forums. :)