Not only did Ubuntu change inittab to event.d/, now they changed the format of files in event.d/ in the move to 7.04 - Feisty Fawn, and I didn't find the format defined in any relevant man page.
I upgraded to 7.04, and svscan wasn't running any more. I added the /etc/event.d/svscan from my previous posting, and when I tried to start it I got the useless error:
start: Unknown job: svscan
Brilliant... So what's wrong now? Apparently the format of the file. The correct format is now:
# svscan - daemontools # # This service maintains an svscan process from the point the system is # started until it is shut down again. start on runlevel 1 start on runlevel 2 start on runlevel 3 start on runlevel 4 start on runlevel 5 start on runlevel 6 respawn exec /command/svscanboot