Oh, hey, this is a good question.
An important point is this is definitely NOT python 3 -- in fact people who have Python 3 installed will get different results when they divide fractions. I should probably address this in the wrapup.
However, glancing at
http://docs.python.org/dev/whatsnew/2.7.html and the Python backwards compatibility policy, I think it's very unlikely that 2.6 would be a problem; the changes between versions look like they're all far enough afield we won't encounter them. --ay