As a fan of city builders I need to strongly disagree here :) What city builders? Crappy Cities XL? Pathetic SimCity 4-5? Sorry, I don't see all these city builders. Actually I can't find even ONE I could play. I don't want them to be "different", I don't want the ability to "import sims", I don't want full 3D pixel perfect map where everything has different shape and you can't align anything.
I think you'd got a nice idea, you just have to find a way to make it different from all the "city builder" games already out there that are similar.
I DO want the standard overused SimCity 2000 or Pharaoh or other clear grid based city builder (where I can see how much space I have left). I would definitely buy a standard oldstyle traditional city builder game (and preferably without any combat unless it's made as skilfully as in Caesar/Pharaoh series). Actually, I hate no one make these anymore :(