I've been thinking about this. I think the best solution is to allow the
deletion of a user, with all of the user's edits assigned to a single
special user (say, "Trash" or "Junk" or whatever). That way, the
references all over wiki would be intact, i.e. they would still point to
somewhere (in this case, the special user) and there would be no need to
rename dozens or hundreds of accounts to things like "renamed-spammer-1"
- the deletion script/specialpage would do the reassignment automagically.
Filip