Comment 7 for bug 147928

I agree, but I think there should be a way to retain the config file you initially said not to use.

My idea would have the upgrade utility automatically use the new configuration files whenever a prompt would have been displayed, and would make backups of the old config files, renaming them with the previous ubuntu release codename (ie "configfile.gutsy" during an upgrade from gutsy to hardy).

After the upgrade, the user could be presented with a GUI displaying which files were automatically replaced, with a diff displayed, and with a button allowing the user to revert each individual file to it's old version. If the user would opt to keep the old version, the system would instead make a backup of the package maintainer's version renamed with the new release codename (configfile.hardy), so that you could change your mind later.

This would prevent the updater from having to know in advance what packages would ask questions, and would also keep the upgrade process from halting to wait for the user to respond mid-upgrade.