It's all too small. It needs to be 3d with gorgeous skies and detailed characters. Great gameplay though; hard to improve.
No 3d will ruin it.
As it did with many rts games that went 2d-3d.
2d ***.
Simcity 4 for ever

(imo).
City's lifes's just, well, boring, you build a few cities play it for 10 hours or so and never touch it again, it's repeative.
Doesn't have it's unique problems with each city like sc4, eg a single very bad spot in your transportation system or a cloud of pollution or full schools. Besides city's look similair, whereas in sc4, every city is different if you know what you're doing.
Ideally I'd like sc4 but even more advanced transportation options than with all current mods out there, and a modern 2d engine supporting 3dmodels like it does now ( so I can download over 2000 new buildings, mods, roads, etc again). And even tougher to play and even more attention to traffic, polution (eg. introduce new ways of countering lets say noise pollution), etc...
So Sc4, but then prettier but not 3d, and even more advanced and customizable and detailed.