In my mind, practicing TDD is what matters most. Which framework you choose is a function of your actual needs. The fact that there are 3 of them doesn't really bother me. I think it's better to have a choice from a small number of frameworks rather than have no choice or have a single choice that might not be the best for your specific environment -- provided of course that this doesn't evolve into a PyWebOff-like nightmare :-)
Grig -- http://mail.python.org/mailman/listinfo/python-list