[geremy condra]
Was it ever decided whether this would fall under the moratorium?
Decided isn't the right word: http://mail.python.org/pipermail/python-dev/2009-October/093373.html
FWIW, I'm a strong -1 on both proposals.
Just add a short get_one() function and a get_equivalent() recipe to your utils directory. That will get the job done (thought I don't expect that you will *ever* make much use of either one). No need to complexify a type that is currently very simple.
Raymond
P.S. get_equivalent: http://code.activestate.com/recipes/499299/ get_one = lambda s, default=None: next(iter(s), default)
The first works with all type that defines __contains__. The second works for any iterable. Neither of these concepts are specific to set objects.