Perhaps this ought to be discussed on python-ideas or python-dev for a bit.  It is not entirely clear that this is a GoodThingToDo(tm) nor is it clear that we want other Python implementations to have to invest the same effort.

The spirit of the language freeze suggests that we shouldn't add this unless we really need it.  The goal was to let other implementations catch up, not to add to their list of incompatabilites.