OK, here is a new patch proposal.  As suggested by Alexander, it adds two functions to email.utils: format_datetime and parsedate_to_datetime.  Adding these does not require having localtime.  In fact, with this patch you can get an aware datetime representing email's current best guess at localtime by doing:

   dt = parsedate_to_datetime(formatdate(localtime=True))

Reviews welcome, but this is simple enough I'll probably just commit it if no one objects.