I have been working with Django for a day or so and it is pretty nice. This past semester (my last!), I learned Rails and it was a great experience. Rails is very nice because it is so well organized and exposes a great design pattern in a way most other web systems do not. I say "web systems" by the way, because working on any web based software could benefit from the way Rails organizes and implements a system. Django does many of the same things as Rails, yet in a more specific way. The biggest example so far has been the concept an admin interface.
In Rails, you have direct access to models through model controllers. Rails expects the developer to solve any security concerns on his/her own. This makes Rails extremely flexible, which is very good when you are looking for a framework to build applications on. Django on the other hand takes a more specific route and enforces an "admin area" paradigm where information on the site is edited through a specific admin interface. This makes sense because Django was created as a tool for creating publishing systems. Any publisher will want editing stages and other public/private features from the get go, so including these in Django makes quite a bit of sense. At this point, I am not sure what it means for flexibility in the long run, but for first impressions, it makes a slick admin interface that seems very helpful.
One glaring difference between Rails and Django is the speed. Running the Ruby Webrick server is incredibly slow. Even running a Rails application locally, there is a lag. Django on the other hand feels blazingly fast. I am not surprised to some extent because there is so much great Python based server code that could have been used. I am hoping to find out more about this.
I should point out that I have just been playing around with Django. I haven't had to develop anything specific just yet. After trying TurboGears, Django has been much more cohesive. TurboGears was very nice in that you learn many different stable and popular packages, yet it is very much alpha software and I think that integrating all the different packages it uses is probably more work than it is worth. Hopefully by the end of the week I can be a guru in some Python web framework, Django or otherwise.