I thought the upgrade would finish unattended but it did ask twice about keeping or overwriting config file so the next morning I had to tell it to keep my Samba config file. That night when I got home I had one more prompt to answer and then it completed & rebooted shortly thereafter. The only hiccup that I’ve seen so far is that Samba would crash on startup or when I tried to open its control panel. I opened the smb.conf file and it looked like there was a syntax change so I commented out some old lines for folder shares and it seems to be working now.
Ubuntu 8.04 Hardy Heron LTS install notes thread on the forums