I tried the project out and was brightly surprised
A bug I noticed was on Windows, in the roo.bat file, the path in the Java command that uses the %ROO_HOME% variable should be in quotes for the case where %ROO_HOME% contains a space. (might be a problem in the sh file too... didn't check)
Also, I think that for a even better start for any audience, there should at least be basic support for internationalization (as in text stored in properties files and translated in a few principal languages) and user auto registration (or have more default users), although it does not seems too hard to do, it would make for more wows.
Just an idea: I could see each spring project having it's own roo plugin and thus add more power to the base commands.