From the Hell Yes, We Work Weekends 'Round Here dept.:
Python 3.1 is a continuation of the work started by Python 3.0, the new backwards-incompatible series of Python. Improvements in this release include:

* An ordered dictionary type
* Various optimizations to the int type
* New unittest features including test skipping and new assert methods.
* A much faster io module
* Tile support for Tkinter
* A pure Python reference implementation of the import statement
* New syntax for nested with statements

python.org