My Thoughts. Would like input.

[MathiasB]

P.S. Authentication could also make it possible to have a system with admins that have access on all servers...

This is in Sauer, and is a feature I personally despise.  I don't trust someone I don't know with admin access to my servers.

They may not have the admin standards I do, and may give my server a bad rep.

Of course there would be a option on the server to disable it :)
It was just a general example.

One could make lists of admin users and share that lists with other server admins. (to give an idea.)
Auth would also make that you don't need to store passwords in plaintext.

Auth also makes it possible to officially register clans, nicknames, ...

If wanted I have no problem contributing to AC by writing the server back-end for an auth.