I ran Migration Assistant to copy the account on my MacBook Pro to a desktop Mac (as in an iMac, Mac Pro, or perhaps even a home-spun concoction if you are so willing?) After doing so, I found that restarting, shutting down, or logging-out took way longer than expected.

Inspecting the shutdown log in console, I found a suspicious message:

5/3/08 11:04:20 AM com.apple.launchctl.System[2] launchctl: Please convert the following to launchd: /etc/mach_init.d/dashboardadvisoryd.plist

Turned out that I needed to remove an incompatible dashboard extension (in my case it was iStat Pro).

Shutdowns, reboots, and logouts are now back to normal again :D