I don't want to nitpick, but in Arena, Cyrodiil was a lush farmland...
I'm hoping for the 200 years to be filled with history and lore.
Only the Nibenay Valley, with the Imperial City as a huge metropolis and the only big settlement around. I can check out the manual to Redguard and confirm this lore-wise. Or just look at http://www.uesp.net/wiki/Lore:Pocket_Guide_to_the_Empire,_1st_Edition/Cyrodiil. I faintly remember Morrowind (either a character or some book) also referring to it as a jungle at some point.
At any rate, the problem here is not how much detail we were given, but how fast Beth decides to change the lore. Much more time between Morrowind and Oblivion, and I would have been satisfied.