Thanks Ned. 

A couple of things. First, you probably know about this, but for future reference in case it might be useful, the install_name_tool lets you point a shared library at a different dependent shared library than the one it was originally compiled to link against (see end of http://www.tkdocs.com/tutorial/fonts.html). This can be sometimes helpful in resolving compatibility issues. 

Secondly, we may want to consider adding something post-install (in IDLE?) where it would detect at least simpler cases of greatly out-of-date Tcl/Tk and offer to download and install a new one. If it were in IDLE, this would have the advantage of not affecting everyone who installs Python, but only (a subset of) those who would benefit. Plus, not being a "you must decide now" like an installer, it could be deferred if people weren't sure. And it would offer to provide a bit more active assistance rather than only "go read a web page".