1) It's not appropriate to document NullHandler at the point you
describe, as that's the API for Handlers. However, it is documented at

http://docs.python.org/library/logging.html#configuring-logging-for-a-library

I will check that NullHandler is added to documentation where the
available handler classes are listed.

2) Unlikely to be backported to 2.5, as it's a new feature (2.5
documentation tells how to create the class in user's own code).

3) NullHandler was placed in the main logging package along with the
other "elementary" handlers which are likely to be of most general use -
the handlers.py module is intended for more specialised handlers.