A recurring question on the #ubuntu channels is how to fix one's sudo / root
account, after /etc/sudoers has been messed up and/or the user has set, and
forgotten, a root password. Usually people are advised to boot from a cd, mount
their root, and fix their sudoers/shadow/hosts file manually.
There could be a tool somewhere in the installer's menu, that would do whatever
it's necessary to restore the root/sudo access to default. An option to reset
normal users' passwords would probably be useful too ;)
Also, sudo seems to depend on gethostbyname(), which usually depends on
/etc/hosts mapping the hostname to 127.0.0.1. I've heard random anecdotes of
/etc/hosts "mysteriously" losing this entry, and also of people accidentaly
messing it up. I believe this tool should check /etc/hosts for this aswell.