> What about having a "Contact-email" then that would replace the
> "Author-email" field, and an "Author" multi-valued field as described
> previously.

Why do we have to add new fields and deprecate others? Just for the sake
of confusing users and breaking existing packages? What do we gain
exactly? There are enough fields available to make the writing of a
setup.py burdensome...

If you have several authors, you can separate them with commas in the
author field and even include e-mail addresses if you want (e.g. "Tarek
Ziadé <tarek@example.com>, Antoine Pitrou <antoine@example.net>"). 

Not every wish for a new "feature" should be satisfied, IMO. Besides,
making metadata complex and version-dependent is the best way to make it
useless.