The REST Dataservices Node is a welcome new feature.
For documentation purposes it would be handy to have a comments field added to the dialogs for creating modules, templates, handlers and parameters.
I have created a restful module that reports .. the defined restful modules, so any user can have a life description of all REST functions available. I currently fill the comments fields manuallly, so this module gives a nice description of the available REST services. (I will publish this module somewhere when I think it is good enough to share).