Graphics
Very nice with a decent computer. Looks like ass on minimum. Optional depth of field effects that are cool, plus a lot of neat filters to alter the look.
I like the art style, but others might be turned off by its more "cartoony" appearance.
Immersion level
Pretty immersive, since you can go down to the street level and alter you perspective in the 3D world, unlike previous versions of SimCity. The simulation also simulates each individual living in the city, and if you're prone to that kind of thing, can get lost following your citizens around as they go about their daily lives. I personally don't really care about relating to my citizens in a sim by sim basis. I'm more of a macro kind of guy, but I appreciate the complexity and strategy that the new simulation engine offers.
Ability to create unique cities
You're not restricted to a grid like in other SimCity games, so you can go wild with curvy roads. The ability to specialize in certain industries also gives each city a unique feel and a role to play. Also, the terrain, and intercity connections are different in each city, so that helps to give each plot of land a unique identity. It's also a byproduct of the (unfortunately) small plot size.
Ambience
Ambiance? It's nice, I guess.
Control given to player (how much power do I have over the city)
You can do a great many things and have a lot of influence over what goes on. You can't control terrain anymore (no terraforming), and the small city sizes are a little limiting. Other than that, though, the options available to you have increased over previous SimCities in most areas (with the exception of a few, such as traffic options, city ordinance options, and targeted funding options).
Future potential
This new SimCity has as much potential as the original SimCity Classic. Envision how SimCity classic improved up to SimCity 4. The devs have that goal in mind for the new SimCity.
Potential issues
Always online sucks. You're subject to server lag, and a required connection.
Things you dont like / hate
Always online
Small city size
Limited traffic data tools
Limited traffic/road network solutions, such as subways
Park placement/aesthetics
Region wall is laggy and disorganized
Service and resource sharing is laggy
Coordinating with friends within Origin sucks, partly due to no group chat
Pathing AI can be stupid sometimes
OVERALL: I've already preordered it. Can't get enough of the betas. Hungry for more.
Hype level: Over 9000