Ted Leung comments on a weblog posting by Robert Martin where he compares programming with statically typed languages and dynamic languages. The result being Robert finds he prefers dynamic languages and Test Driven Development.
It seems that Python and Ruby are really catching on as popular dynamic programming languages. It's a shame that Common Lisp, Scheme or Smalltalk don't get as much 'good press' as these languages already have many of the features that are just starting to appear in the more popular languages.
Part of the reason could be that for Ruby and Python there is only one implementation. Users can rely and trust and extend that single implementation. Whereas Common Lisp, Smalltalk, Scheme, etc all have many implementations. While this is good in terms of choice it means that code implemented in one may need to be ported to others so there is a bit of fragmentation there. And the user needs to decide on an implementation to use.
Ted mentions Dylan as a possible chance for a Lisp like language. The name Dylan comes from DYNamic LANguage. Andrew Shalit posted on comp.lang.lisp a few years ago that when they were working on Dylan, as the language developed more static features, some people joked it should be renamed to come from STAtic LANguage. This is perhaps a bit unfair and is probably because Dylan combines both static and dynamic typing and many of the developers working on it came from the heavily dynamic Common Lisp.
Gwydion Dylan is a Dylan implementation with reasonable development activity and runs on many different platforms if you want to play with the Dylan language.