The amount of assets available and the quality do not currently match the Regional style. If you want to make a world map that references several regional maps (drill downs) then there is just no good way to set up a nice World map.
Ideally, all HD assets would work on the world style maps but they just don't scale well.
At least POI elements and towns and such would be nice to see represented on the world stage for all the race/regions available in the Regional style.
