I look forward to having dynamic languages improving on the JVM. When I moved from doing all of my work in Java to learning and doing mostly Lisp at work, I learned one of the biggest headaches of coding wasn't a lack of static typing (strong is not the issue), but NullPointerExceptions, which doesn't plague my Lisp code. And for the defmethods where nil's might cause an error for not being handled, NULL is actually a type that I can code for to avoid the problem entirely.

Another thing I realized was how much code, or rather code-supporting files, where already in other languages around Java. There's Ant, ejb-jar, properties, SQL, numerous internal and external XML, Javadoc, annotations, manifest, xslt, jsp, html, css, javascript. Point 1: don't worry about Python, it's a better language than many of those you're already using with Java. Point 2: with Lisp, it can be all Lisp, or you can integrate with other such languages where you need to. I think the reason Java has all of these satellite languages (especially XML) and files is because the language is so weak and inflexible - Lisp is as flexible as XML, but works nicely as a programming language.