Heck yeah, I can't wait for Civ4. Sure, the units look idiotic. And they took the hallmark attack/defense pair out (why?). But the borders look nice, and religions could be interesting.
Civ3 was good, but the corruption was incredibly stupid, and the developers just refused to do anything about it. What is the point of a conquest game if you can't conquer the world?
The expansions eventually helped a little with this, if I remember right though. Somehow, all my civs are now a bunch of commies!
I would love a SMAC2. SMAC's only problem was that the endgame brought everything to a halt. You didn't even get to micromanagement problems in the endgame because the plant's units would get in your way first. Oh gee, I love watching 50000 mindworms moving across the world, thanks! Other than that, it was a stellar game with an interesting story.