Python 2.4.4 is likely to have Universal Binary build support. (That is, building Python from source on an Intel Mac will produce a correct Universal Binary that runs natively.) Python 2.5 beta builds have Universal Binary build support, and that support will be back-ported to 2.4.x in the hopes that Apple will include it with the next version of the operating system. According to this post, the version of Python 2.3 that Apple includes today is "broken" on Intel Macs. (Scare quotes around "broken" not because I doubt it, but because I don't know the nature of the breakage.)

MacPython 2.4.3 is a Universal Binary. I can come up with some guesses as to why Apple wouldn't just, say, distribute MacPython, but I don't really know.