Wait. What? Why? Is this officially confirmed/explained?
Sorry, let me rephrase because I just notice how ambiguous my statement was: with certain larger cities, as soon as you leave the central areas you will notice that the graphics switch from real MS Bing data using some kind of photogrammetry routines to make up 3D buildings looking similar to the real world equivalent, to only the 2D floor map of the cities. So you get a really great looking downtown while the suburbs look more like the old well-known default buidings used in the old-fashioned flight sims.
The point I don't understand is that it seems to be more restricted than the Bing map service if you check that in terms of where it has 3D maps and where it only offers 2D floor tiles. So I very much hope this is still a work in progress issue.