What is the likelihood that __nonzero__ could be renamed (at some point in the future) to something a bit more intuitive, like __bool__? I know there would be a lot of user code to change, but assuming one day the hammer will drop and everyone's __nonzero__ will have to change to return a bool, I wouldn't mind seeing the method renamed as well. Or is this a lost cause at this point?
I think it's a lost cause. It's one of those minor details that might be considered wrong with 20/20 hindsight, but not wrong enough to want to bother fixing it, given the cost (to the user community) of the fix.
--Guido van Rossum (home page: http://www.python.org/%7Eguido/)