Then I ran the Software Install and Restore disc included with the new computer, selecting the option to keep network settings. From the limited description in the manual and/or help, this seemed like the way to go and it worked. This got me to 10.2.3 (when 10.2.5 was current), but Software Update more or less took care of that from there.
I had to turn Sharing back on, reinstall the Developer CD, and reinstall the Microsoft Intellimouse drivers. But domain hosting worked, Mail works, Safari bookmarks are preserved, Safari password, DragThing, etc. I think this saved about two days.
[robg adds: I'm not 100% positive I would recommend this practice, as there's now an old drive in a brand new machine. Something like Carbon Copy Cloner would probably accomplish the same result, but let you use the new drive in the new machine - I'm not sure, though, not having tested it in such a manner.]

