Not if you keep your iTunes.xml out of firefly’s reach.
There is a perl script that handles rating, but its still in beta and requires an unslung NSLU2 to work correctly. It’s part of http://billiatjapan.netfirms.com/Tools4Roku/
However, when you rate songs there, their rating will only be updated in firefly’s database, not the actual files.
Managing rating across music player software is cumbersome, to say the least 🙄 😕