Ryan Paul at Ars Technica has an excellent write up of a hackfest sponsored by OLPC to start implementing a plan to ease the future maintenance of the Python bindings for GTK+. The OLPC project makes considerable use of both Python and GTK+.
The plan is to incrementally phase in new bindings that take advantage of GObject introspection alongside the hand rolled bindings. The new implementation, PyGI, is off to a good start and will eventually replace PyGTK. I believe it depends on Python 3.0, so adoption of the latest version of the language would also be key.
I am glad to see Paul emphasizing how GObject introspection will reduce the cost of bindings for high level languages and strongly but indirectly encourage GTK+ hacking by developers of all stripes, at all levels of skill and experience.