I don't like the idea of "15 maps" instead of the world data. Biggest problem I see is that this will it will not be possible to mod in other theatres, anyone ever thought of german submarines in SHIV??
What exactly they are going to do is in the stars, but I hope they will at least do in a way as good as SHIII. If the terrain is limited to the current TOO, so be it, but please don't limit the theatres so much as to have any real "borders" (like LOMAC for example) - that kills immersion for me, even if I don't want to go anywhere special.
The world was one of the parts I liked most about SHIII. Satellite data is around, freely available, and they (UBI Romania) showed how a believable game world can be made from them .. not that usual hand made phantasy stuff and lame arguments like "of course it not possible to model x with that amount of detail so we thought sticking with y would be cooler". Since playing CFS2 I cannot go back to playing crap on tiny, handmade areas, when there is already a perfect solution. Therefore, my advice to simulation developers is: always use satellite data, it's free, it's good and it covers the whole world, + you can fire the map editors, they're low grade personnel anyways