That's exactly how I see it coming!
I will assume a lot in the next passages of text, but I've thought this since I had the first pieces of info (and especially since the screenshots show irregular borders!). So shame on me if this is completely wrong, but I'm very sure about it.
IMO:
You will add single tiles to the cities radius, choosing what you need and specialising the city this way. Cities will have irregular shape, making "dotmapping" no longer important. It will be much more natural to realize what recources are workable when you found a city. Overlap or "Oh-damn-I-have-to-found-a-useless-city-just-to-get-those-horses-on-that-stupid-little-island" will be non-issues.
3 rings of tiles around a city (was it 36 alltogether?) doesn't seem like what will actually be worked by EVERY AVERAGE city, just what the maximum distance is. I guess there will be a minimum distance between cities (2-3 tiles) and maybe even a maximum number of fields per city (20 maybe?).
It will probably be effective to build average-sized cities of 15-20 tiles, but you will have more flexibility than in Civ4 to make some use of this hard-to-reach tiles e.g. on peninsulas.
ADVANTAGES:
-No overlap
-No unused tiles inbetween
-More flexibility to form your borders
-REALISTIC BORDERS!
-A cities fate is not decided when it's founded, but in a constant development process
-In theory, this should be easier to understand by the AI!
-You could trade single tiles with the AI/human players
-Empires which visibly consist of more or less important provinces
-Easier city specialisation
-Easier to sacrifice tiles for forts etc.
Another bold
guess: Workers are gone!
Why? we have one unit per tile, so they don't fit on the map (no stacks!). Instead, you will choose tiles your city will work, and worthier tiles will need more "culture" or something accumulating before they can be worked. Making it a sound choice to place cities closer together in fertile areas, for example.
And no, this doesn't feel dumbed down, cause workers are clumsy to use and unrealistic. They could make it just as interesting and tactically deep to place cities and develop them. It's the variety of possible improvements, not how you place them.
EDIT:
IF I'm completely wrong I'll take Brainy Smurf as my profile pic