In distutils_src_install there're some ${D} yet. For example sys-apps/file with USE=python doesn't install.
Huh? I just installed sys-apps/file[python]: Installed versions: 5.03(06:07:33 PM 08/11/2009)(python
I can't reproduce it here myself either (using file ebuild with USE=python), can you please verify again that this is (still) a problem for you?