Its probably not gonna happen, but it'd be neat if the next TES game was set on more than one province.
I still want them to just make it so the next game connects with Oblivion. I'm pretty sure porting Oblivion to the new engine they'd use would be easy peezy. Then they'd be able to market it as the current game and "Ultra compatibility with previous TES Oblivion!" Then people could screw around on Cyrodil AND the new area.
Heck they could get a small crack team converting morrowing and market the largest single player game ever made.
After that a few small edits to make it so you could have a buddy or two come play with you and they'd outsell most games on the market.
But...that's just me bringing up the obvious quick ways to get money and good reviews. It'll be overlooked and never done.