Well, I thought I'd fixed this problem but it seems that shutdown is still broken with JmDNS.
While I'm trying to solve this problem, please either "Force Quit" Lilith ((Right-Click, Alt, Quit - no harm will happen to your system or any lilith data) or start it without Bonjour support, i.e. with the -b option.
Startup command in Terminal is
java -jar lilith.app/Contents/Resources/Java/lilith.jar -b
If you are a Mac user and don't instantly puke if you see the terminal window you can also kill lilith using
kill -9 <lilith PID>
You can find the correct pid by issuing the command
ps -ax
and searching for lilith in the list that will show up - but you'll already know this because otherwise you'd puke if you see the terminal window :)
Anyway, have fun.
A deadlock on shutdown is still acceptable, I hope.