Printer sharing worked fantastically on 9.04 Jaunty but won't work on 9.10 Karmic. First of all, enabling printer sharing won't make it broadcast the printer service via zeroconf (Bonjour). I can get around that by manually creating an Avahi service with a config in /etc/avahi/services/. However, the real problem pops up when I try to add the shared printer to the other computers in my network. On Windows when I try to add the shared printer, it says "You do not have sufficient access to your computer to connect to the selected printer." On a Mac, it will let me install the printer, but it will not let me submit jobs to the shared printer. Ubuntu 9.10 can't even discover the shared printer.
For now, I will stick to 9.04. I hate seeing what seems to be a regression in 9.10.