I just posted version 0.6.6. It appears I accidentally changed something in the build config for versions 0.5.2-0.6.5 and there was an invalid MANIFEST.MF fie generated, so the plugin didn't launch. I've fixed this.
I'm also happy to announce that this project will now generate basic Open POJO configuration (http://code.google.com/p/openpojo). So you have choices (but no more excuses) for Unit test generation.