James, I've brought this up a number of times over the last year or two, and technicaly, no, there is no support for alternate names, and it's a touchy subject here because of what I'd call arcane cataloguing practices that have influenced MODS (and now MADS).
Aside: I had an interesting conversation over lunch at the Access 2005 about this with a few librarians and an archivist. I was explaining it made no sense to me that in the 21st century library cataloguing practices (and the XML formats that serve them) still focus on names. Names, put simply, do not do anything, and are simply labels for more fundmental objects. People author books.
Anyway, the interesting part of the conversation was the archivist explaining that their catloguing practices are different, and that they indeeed tend to focus more on the objects (people, organizations, etc.).