I dont think we have to worry too much, although I am a bit concerned.
I have been playing Settlers until the 4th edition, and I was real excited when I found they built a part V (called Heritage of kings). Downloaded the demo recently, but it was a total let down. They completely raped the game. No more logisitics management, careful control of where and how to place buildings, no more carriers. It's just another RTS.
You set serfs to gather wood and food. You put buildings in appropriate places, mines on mountains, farms on grassland etc. Fill them with units, do science just like RoN (4 types, 5 advances --> no depth...) build units and fight. It used to be so much fun to build an economy, now its the same as all RTS games.
Coming back to Civ 4, it's still turn based. You still gain exact resources for each tile you work. There are no gatherers as in RTS's(hate those). There is still a tech tree (but you dont have to discover all). Concepts like culture, diplomacy, trade have improved. You still build stuff with shields (although called hammers). You still grow a city if the food box fills up. You still cultivate your squares with workers (sea with work boats) only more options. Annoyances like corruption and pollution have been replaced by more managable concepts.
What I expect is a similar game with a different look (3D) and a lot more depth in decision making. What to build where, which improvements to build. What your trade network looks like, which techs to go for, etc.
Personally I can't wait.