Changes 1.5:
Django 1.5 introduces support for a configurable User model. The basic Django User model is still around, of course, but now there's first-class support for specifying your own model and having Django's auth system make use of it.

Django 1.5 is the first Django release with support for Python 3 (specifically, Python 3.2 and newer). Python 3 support is still considered experimental -- largely because it hasn't received as much real-world testing as we'd like -- but a Python 3 porting guide is available if you'd like to give it a try, and we will be considering Python 3 compatibility bugs to be blockers for future releases.

Of course, if you're still comfortable with Python 2, Django continues to offer support for that just as we always have -- though note that the minimum version for Django 1.5 is Python 2.6.5, and Python 2.7.3 or newer is strongly recommended.

Django's documentation has also gotten some pretty significant work; the main documentation page has had a bit of a facelift to make things easier to find, the existing tutorial got some refurbishing, and several new tutorials -- including some more advanced topics, like writing an app you can reuse in multiple projects -- have been added. And the documentation for class-based views has been significantly expanded, which should make this feature a lot easier to understand and take advantage of.

(adam)