"I would love to see this working on NetBeans 7. Any news on that front ?"
i just downloaded nb 7.0.1 out of curiosity, and much to my surprise ruby support is available via a plugin.
Of course I had to try to get off working. I used the old nb-1.0.1 package I had laying around, and while it failed to install initially due to missing jUnit4, I went and reactivated the plugin from the plugin dialog, and it worked for me.
I tried nb-1.0.1 on Netbeans 7.2 but it didn't work
What's the current stable version of Netbeans. 7.2?