A post was made on Javalobby in the response of Rick Hightower observation on fastest growing frameworks. According to graph it is clear that there are more jobs of JSF and its demand is increasing as compared to other web frameworks.

Luckily I got chance to work on JSF in my previous job, and I really enjoy the work of JSF blended with some controls of Tomahawk. The framework is great to work.

And let me tell you, in Pakistan there are a lot of jobs that require skills in JSF. In my current job I am working on Struts, and I really missing JSF very much.Because in JSF things are very automated, clear and easy to configure rather in Struts. JSF is developed for RAD, and if you are creating a new application prefer JSF because JSF is built with integration and extensibility in mind. Strategically, JSF should be the target of new applications.I cant say anything about Rubby, Spring and Tapestry because I did not work in them. But I will surely express my experience if I got chance to dirty my hands on later said frameworks.