Depends what you mean by "supports". Alfresco Share uses the surf framework which is a JavaScript/Freemarker/WebScript framerwork.
Alfresco Explorer is a JSF interface but I think its unlikely to be moved to JSF2.
That's not to say that you can't build your own JSF2 interface to alfresco.
You should also be able to use Alfresco WCM with JSF2 since its fairly agnostic of the platform it is managing.
