You can detach the display in each zone and drag them to different monitors
This is the way to do it.
Detached Displays remember their positioning and fullscreen/non status on a per-Zone basis. So, you can just detach the display for each of those Zones, move the display to the proper monitor, and then double-click it to go fullscreen. As long as you don't close the display, it'll stay there. Even if you do close it (by clicking the "bring it back" link or whatever), it'll remember where it was and what size it was when you open it again.
Basically, they are a drag-droppable way to move per-Zones around and position them,
even if you want more than one on one monitor.
It sounds like you may be a few years ahead of us
I don't actually think MC is that far away from a simple way to do this. The main problem seems to be (from an outsider's view, of course) to be UI.
The main issue is that Theater View and Display View share the same Options -> Tree and View -> Full Screen setting. What would work better would be this:
Options -> Theater View -> Display Settings -> Monitor (and an accompanying Resolution control): This defaults to "Same as current" and is NOT Zone specific. Works just like the current one only it is Theater View only.
Options -> Video -> Display Settings -> Monitor (and, again, resolution): Again, defaults to "same as current" but this time is Zone specific like all the other stuff in Options -> Video. This one controls Display View.
That way, you could easily have Theater View set to "Same as Current" (or set to somewhere specific) and cycle between Standard/Theater Views there, while your different Zones have their own Full-Screen Display Views that automatically go to the proper monitor for each zone. You'd just set the Monitor setting under Video to the proper display for each Zone you define.
MC can already accomplish all of the same stuff "playback wise" simultaneously (fullscreen playback, via a Detached Display, on one monitor, and Theater View on another; multiple separate fullscreen displays per-zone, and all of that). The UI to pre-set it is just not very good if that is all you want (to set it once, and always have video from a particular zone go to a particular monitor).
The Detached Displays are fantastic for "on the fly" setups (and, like I said, it lets you have multiple video windows open on one big display, which is useful for things like Eyefinity displays where multiple monitors show up in Windows as one huge display).