I'm currently looking at options for building a high traffic, content (text and images) based site, nothing especially innovative. Is Apache and mod_python as stable and scalable as Apache and PHP?
nah. Use Apache and mod_wsgi.
(mod_wsgi runs the Python app in a separate process, which means that those Apache processes that just serve images will not be weighed down by a Python interpreter).
we're using apache+modwsgi to serve django, and tornado (by itself) behind nginx. both have been excellent. gunicorn looks to have a bright future, but i haven't played with it.