I have tried to use OmniFaces' VDLDoc [1] for generating RF5 VDL documentation in a feature branch:
https://github.com/richfaces/richfaces5/commit/06424ee7725f999217d5e816461183a48a64d989
The result seems pretty good, let's build a feature branch to see it.
For anyone following along, we decided on IRC to go with the "vdldoc" Google Code project to generate the RichFaces VDL doc.