I think we don't need a one-size-fits-all all-powerful date-time formating solution. ;)
It's probably impossible to create one, but I think there's also no reason to require people to invent the wheel over and over. I've seen enough broken code attempting to do date/time formatting that I strongly prefer the creation of a few standard solutions that will work for most people, rather than only giving people the low-level bits to work with.
Another thing to consider is that for most apps, the choice of the date/time format should be taken out of the hands of the programmer and placed into the hands of the user, through some kind of preference setting. I18n and L10n also strongly suggests to take this route.
--Guido van Rossum (home page: http://www.python.org/~guido/)