The basic idea is that the architecture bit of get_platform() should 
tell you something about the archicture for which a build is valid. 
That's why 'i386' or 'ppc' is not very useful for a universal build. The 
original author of the universal binary support choose 'fat' as the 
architecture designator for universal builds ("fat binaries").

Somewhere along the way the calculation of the architecture string got 
messed up, resulting in the current situation. That is, the current 
situation is not as designed by the original author of the universal 
binary support code.

Another reason for fixing this is that setuptools uses the platform 
designator of the current system and a downloaded binary archive to 
determine if the two are compatible. In the current situation univeral 
binary distributions built on a PPC system don't work on an i386 system 
(as far as setuptools is concerned).