At the Rich Web Experience 2009 conference, [Matt Raible][1] presented [a very insightful comparison of "kick-ass" web frameworks][2] including Flex, Google Web Toolkit (GWT), Ruby on Rails and Grails. I appreciate his "right tool for the job" approach which moves beyond technology dogma towards real solutions. He includes some very revealing charts comparing jobs posts, [StackOverflow][3] posts, mailing list traffic and other stats. Check out the slides from his presentation:

 [1]: http://raibledesigns.com/
 [2]: http://raibledesigns.com/rd/entry/comparing_kick_ass_web_frameworks
 [3]: http://www.stackoverflow.com