Looks like a new SimCity trailer was released at GDC (Game Developers Conference) and even though it's a teaser trailer, believe me, it's welcome news for SimCity fans like me who've been painfully waiting for a true successor to the 2003 SimCity 4. SimCity Societies was really just SimCity Lite and targeted at casual gamers - not that it was a bad game, but just that it wasn't really SimCity.
However, I think Maxis need to be careful in not making the game ridiculously complex with heaps of micromanagement like Cities XL and of course not so basic or casual like the original SimCity or SimCity Societies. In particular, the part where they mention your city will look and feel different depending on which industry you specialise reeks of SimCity Societies. I think a good compromise would be gameplay similar to SimCity 2000 or 3000 where there's just enough options to keep a player busy without going overboard in the complexity department.
Oh, also note that the game isn't actually called SimCity 5 as many news agencies have decided to call it. This leads me to believe this is in fact a reboot of the series (seems like the 2010s is the decade of reboots!).