doko has closed the downstream bug on Thu, 19 Nov 2009, with the reason that .py{,c} are not data files in the FHS sense. (Note that even Lisp where code is data (and the reverse) is installed both under /usr/lib and /usr/share on Debian, so I don’t really know what to think.)

About the more general FHS problem, Tarek (the distutils and distutils2 maintainer) has a draft PEP about fine-grained control over every installation directory, so FHS layout for Python projects will be easily possible in the future. See http://bitbucket.org/tarek/distutils2/src/tip/docs/design/wiki.rst (product of Pycon 2010, done with OS packaging experts, doko and other people). As for Python itself, we’ll see if there are other bugs about FHS compliance, but it seems good right now.