XSL: Flow maps

Again, I'm referring to the April 21 XSL working draft. Section 4.1.1
"Page-masters and page-sequences" says: "In later versions, a flow-map
object may override the default rule in specified cases, to allow flows
to be associated to regions differently, through some syntax and
semantics to be designed later."

What is the status of the flow-map object design? Is there a publicly
available working draft which I can review to get a sense of how the
flow-map object might work? (Of course, I'd understand that such a
working draft would be highly subject to change).

Rick Rogers, Fenestra Technologies