I had a server with a complex network configuration: 2 network interface cards, with various VLAN configurations. When upgrading, i decided to use Migration Assitant only for the Network Settings. It's nice, so i deselected everything but the Network Settings. It took 16 minutes and a reboot. When the server came back up, guess what? Network Settings were not imported at all! I think it actually imported some other settings, but no Network Settings. Boo.