This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I will review Python a bit more and then I will post my thoughts about additions. I just began to study Jython within the past week. One thing I can say is that I was attracted to Groovy since the syntax was so similar to that of Java. Jython always seemed to have a "different" syntax than Java. This is one of the reasons why I think a reference sheet would assist my efforts.