This makes me worry that none of the major JSF UI component libraries will be using the built-in AJAX library because it doesn't have enough features. Will JSF 2.1 complete the AJAX functional requirements of RichFaces and IceFaces?
We will both advocate for vendors to use the built-in Ajax library and gather feedback as to where it is limited so that we can improve on it. Jim Driscoll has done a lot of work with the Ajax API and would likely be able to comment further.
Can anyone comment on how the JSF 2.0 AJAX library compares to other major Java web frameworks? Is it on-par, ahead of, or behind other web frameworks?
It is certainly more conservative simply because we don't want to dump in the kitchen sink and then regret it after the fact. However, I know that the Ajax interaction itself is very clean, simple and should be very straightforward for most developers to understand. Again, Jim's blog is likely the best resource to get a feel for how this Ajax library is used for you to judge for yourself.
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Another question I have is about hiding managed beans from views. If I were to build a JSF 2.0 application that lets users customize the screens with themes/skins, I would not want them to be able to access any and every scoped bean in the system. To have this level of control I might need to use a web framework that gives me more control such as Struts 2, because it uses Freemarker and/or Velocity.
I'm really not sure I understand what you are getting at. Why does Freemarker or Velocity give you more control over bean access?
Have you heard of anyone mixing JSF with Freemarker?
I talked to a developer at JBoss World that was interested in creating a module that would cater to this integration. But nothing concrete at this point. I can say that the whole idea of the VDL is to encourage other view languages to emerge.
-Dan