I was a big fan of how "Awareness" was universal (everybody got it, that displayed all cities on the map to the player that cast it) but "Nature's awareness " was earth/nature magic only (showed everything in the world)
In this I would want something similar... like an awareness (perhaps another name of course, but just showed cities) then an "earth's awareness" that revieled cities, units, and dungeons on ground; "sea's awareness" which would show all the oceans and lakes, the units on/in them, and cities with ports.
Yeah, I wish we knew if there would be different planes. I'm sure they are still working on getting the base map working right before they go considering the addition of extra dimensions to it, which would explain why they have not told us fet if they are going to do it.
As solam suggests, we will know more when it comes out. Beta 0 draws closer though, so it won't be too long before we have some insight.