I just upgraded to Lion and it's been ("Upgrading iCal calendars...") for over 30 hours now. It appears to be stuck at approx 75%. The progress bar has not changed in 20 hours, but I do see CPU Time increasing, the CPU% changing and the # of threads changing (from 6 to 7 to 6, etc.). How can I tell if it's really doing something? What happens if I FORCE it out or reboot? How long is too long to leave it be?