For some reason, I get some search traffic for the string "Django Java". I don't know why. Still, I want to address what I think these people are searching for a bit here.
First of all, Jython-compatibility is in Django 1.0.
Still, there is no framework like Django being written in Java. There's not. There are hundreds of web frameworks for Java, though. On a very high level, some focus on abstracting the web away (Echo2 and 3, Eclipse RAP, Google GWT), some focus on abstracting Java away (Grails, Tapestry), some find a way in the middle (Spring MVC, Struts2).
The one thing that comes close to Django in my opinion is Tapestry 5.0. However, Tapestry does bring with it a lot of very advanced web development architecture that is not necessarily what you're after. Working with Tapestry requires you to subscribe to component-oriented development and the usage of a dependency injection container and if you want to realize its full potential, you'll need a couple of additional technologies like ORM in the form of JPA or at least plain-old Hibernate.
It is important for me that I make the point that many of the current scripting language-based web frameworks seem to be going through much of the learning curve that led to all these Java technologies, but some, like the Java AOP stacks can be avoided completely by using a language that has functional aspects to it, like Python or Ruby. Not PHP. Never use PHP for anthing serious anyway.
So, by all means, if you're developing in Java, either because you have to, or because you've made a conscious decision based on legacy code, for example, or the availability of a mature library of some kind, go ahead and check out Tapestry, which also allows you to develop big parts of your application in Groovy anyway, if you shy away from compiled languages.
But if you're searching for light-weight, quick, easy and architecturally sound web development and prefer to develop in Python, go for Django itself. Since version 1.0alpha2, Django is compatible to the next Jython release (2.5). That means that you can use all the fancy Java libraries you want from your Python code (it will not feel pythonic at all times, though) and still use Django's excellent infrastructure. This will also allow you to run Django on a full-fledged JEE application server.
I, myself, am a bit undecided on what framework to use with Java as there's also Grails to consider and if I had to choose between Django ORM and Hibernate/JPA and I'm using Java anyway, I'd probably go for Hibernate as it has a lot more mature features (like full Lucene integration in Hibernate-Search, "sharding" and most of all: aggregation support, a basic feature that Django ORM still lacks).
So there you go... it again comes down to the question of what tool is the best one for the job at hand :-). I hope this post helps those people who come here searching for an answer. If you need more information, just email me.