Downloaded it, but not played it much yet.
Don't really like the cartoony graphics, preferred the old style, but there are some nice touches. Tend to get used to these things pretty quickly though.
Gameplay seems like you have a lot more options and requires a bit more strategic planning. Barbarians are 'smart' now and have scouts who scope out the best places to attack or pillage rather than randomly wandering about on suicide missions. Cities can expand over multiple tiles, citizens need housing for growth, also more diplomatic options.
Looks like a bigger change than from civ 4 to civ 5 with greater complexity which is (hopefully) a good thing. Will definitely require a different paying style.
I like all of the civ games though so imagine this one will be good too. Will give it a bash tomorrow.