It IS. I said so in my OP.
I read your OP, I wasn't sure how to interpret "smaller 'big' cities". That could just as easily mean a large, non-major city as it could a major city.
Any way, hopefully there will be a lot of interior content. If anyone's played Banasplit's Better Cities for Oblivion, there's a huge section added underground with shops and quests and everything. It would be awesome for it to be like that...
Of course it probably won't be.