i suppose very first should be checking depenencies on closed source apps to see if there are any using 2.3 or 2.5 as we can't help but keep a version around for them, so it may effect how we approach everything else.

then, check aapo's 2.7 meets all requirements, optification, build options etc. get preferred version into devel.

identify 2.3/2.5 external modules, push new versions as python2.7-modname.

identify list of packages depending on python and those using it as builddep, update to use 2.7. build, test and push.