Is JSF used in the enterprise, or at least used?
We use it at my company at "Enterprise", I know the previous two companies that I worked on have used it on various projects. The only other framework that was more popular was Struts 1.
This page provides some "real" JSF links.
Yes, it is used.
Widespread use? I do not think so. It is probably used more than Wicket, but less Spring MVC, at least from conversations with my peers.