I blogged about this Javacast the other day, and I finally got around to listening to it today. Tune into it at minute 1:22. The guys describe a small web app that they built using a "lite" Java stack - Spring and Hibernate instead of the full J2EE stack. Time to build - 4 months. Ok, they decided, on a whim, to try Ruby on Rails. Time to build?
That's a pretty amazing productivity jump, and they were pretty shocked. They went on to state that dynamic languages just have it all over Java in this sphere, mentioning Ruby, Lisp, Python, and Smalltalk (stating that Ruby has momentum).
Then there's an interesting riff starting at minute 1:26, where they go into Continuation based web development, and they point out how much simpler things like Seaside are - they went so far as to say that they figure that in 3-5 years, we'll all be doing development like this. They mentioned Seaside and Squeak specifically (note - Seaside works in VW as well). They point out that you can't get there in Java, because you can't do Continuations. Instead, there are frameworks that build huge state machines (complexity alert!).
So, if you want the power and productivity now, you can grab VW or Squeak and start using Seaside. Or you can get the all too typical pale reflection in Java...