I loved Master of Magic, didn't really get that much into Lords of Magic or Age of Wonders and this game looks exactly like my cup of tea with all the features that I missed:
1. I love RPGs and like almost every game that tries to combine any other genre with RPG elements. As I am not the most hardcore TBS player (not a good one at least), added RPG elements will be perfect for me.
2. I like the organic-style city improvement.
3. I dig the art style (except for the character's faces)
4. I am sure the guys at Stardock will eventually create an AI and diplomacy system that will blow everything else out of the water. I am an avid fan of diplomacy in games, I can spend hours bartering and arguing if it is good and responsive and the opponent acts "with character".
5. I like to create adventures of my own and the modding tools look promising.
But the most important reason for me is:
6. The gameplay looks like it is mandatory to actually explore and act within the world instead of simply building a couple of cities in your region after the same formula, staying home, spamming troops, doing some research until you are ready to nuke all the opponents. I am really looking forward to the fact that crucial resources are not produced by the improvements themselves, but that they only amplify the stuff that is within your sphere of influence, so you have to go out and find them first. I hope this makes for a lot of tactical dilemmas.