Meh, I'll pass on this one just like I did Sim City 4. Not because I don't like the game style, but the increasingly complex evolution.
Sim City was, for me personally, quite a nice challenge to balance everything out. Sim City 2000 got more complicated, certainly, but it was still possible to build a nice city without *too* much trouble, but when I tried SC 3000 I found there were just too many things to try and balance. While it's evidently possible, it stopped being fun to try and do that, so I didn't dig deep enough in to the mechanics.
I don't see any let-up in that aspect of it, so I'd expect this to be little more than pretty'd up Sim City 4 with vague multiplayer aspects (who can build the biggest city, really, with some vague nods to helping or hindering your neighbours)