For what it is worth I did the kubuntu upgrade to 7.10 using adept (you have to enable testing repositories if I remember correctly). It downloaded all files fine but hung up in the configuration. After numerous issues getting Adept to close down I just rebooted then did ctrl+alt+f1 and logged in. Here I did a dpkg auto configure recommended by apt-get dist-upgrade and followed through all the prompts to get a fully working upgrade.

Also remember that if you use nvidia/ati proprietary drivers that you need to get the most recent version of envy which supports 7.10 before hand and then run the envy -t at the command line to get your graphics back.