I'm sorry I didn't see this when you asked (two weeks ago now).
I wholeheartedly support your move to PostgreSQL, but if anyone else on the list is stuck in the same situation, about a year ago I adapted the Django MySQL backend to use PyMySQL[1], which is a pure python interface to MySQL, is essentially a drop-in replacement for MySQLdb, and *is* Python 3-compatible.
You can just easy_install (or pip install) django-mysql-pymysql, and use 'mysql_pymysql' as your database backend, and you should be set.
Alternately, you could wait a bit; Andy Dustman mentioned on his blog a couple of months ago that a soon-upcoming version of MySQLdb could be released with Python 3 support [2]