Sage and Python 3?

Have you ever wondered how difficult it might be to switch Sage from Python 2.7 to Python 3.x?  Some students in my Sage course made a webpage that summarizes the Python 3 support status of the Python packages on which Sage depends.

Interesting examples:

• Matplotlib doesn't support Python 3.x at all yet.
• Mercurial doesn't support Python 3.x, and they don't have any plans to do so. (Which is another point in favor switching Sage to GIT.)