finally got matplotlib to install...

the key is reading the readme, not just the make.osx file.

These commands Just Work:

make -f make.osx PYVERSION=2.6 PREFIX=/Users/adam/repos/mpl_dependencies/ fetch deps mpl_install_std
make -f make.osx PYVERSION=2.7 PREFIX=/Users/adam/repos/mpl_dependencies/ fetch deps mpl_install_std

while, e.g., this one:
make -f make.osx PYVERSION=2.6 PREFIX=/Users/adam/repos/mpl_dependencies/ fetch deps mpl_install
didn't. I guess because that one doesn't actually install anything.