Ian Bicking hits on one of the intangible benefits of dynamic languages:
Back to reliability: one way to decrease bugs is testing, but another way is to decrease the amount of code. Code deleted is code debugged. Static typing can decrease the number of bugs, but decreasing the amount of code is a much, much more effective way to decrease bugs. If you can have both -- short code and static typing -- then more power to you. I just haven't seen it myself.
Whenever I read about some of the larger blog server systems, I'm absolutely stunned by the amount of code involved - the core of this server is 21 classes - plus 4 for generating the syndication feeds, and another 24 for the various servlets running (it's one class per servlet - you can do that differently, but I didn't). Less than 50 classes for a fairly full function blog server. And yes, having less code makes it far, far easier to manage.