During a meeting in the Community Corner (java.net booth) with James Gosling, a participant asked an interesting question: "Which Programming Language would you use *now* on top of JVM, except Java?". The answer was surprisingly fast and very clear: - Scala.
Btw. I will give tomorrow two talks in the community corner one about GreenFire (heating system on Glassfish / Java EE 5 - which saves energy), the another one about underworld (Java EE 5 / Glassfish backend for virtual reality). So see you if you like!