First person info
Generally speaking, the civ differences are more significant, more logical, and more balanced than in AoE. I realize that "more significant & more balanced" sounds like an oxymoron, so let me explain.
More Significant -- the civ bonuses are generally bigger. Instead of cheaper monks, for instance, at the moment one civ now gets monks that can heal at a distance. Instead of higher-hit-point villagers, one civ gets 3 extra starting villagers (but only 50 starting food instead of 200). You get the idea. NOTE: these particular bonuses, as with any bonus, may be dropped (because they're not fun, or lead to some kind of problem). If they're dropped, they'll be replaced by new, superior, ones, so please don't get your heart set on something I've mentioned and then be disgruntled if it's not in the final game.
More Logical -- civ bonuses work together, instead of against each other. If your civ has crappy anti-cavalry units, you'll also have superior cavalry. If your civ gets bonuses for gunpowder units, you won't be penalized on gold-mining.
More Balanced -- we feel we've learned a lot from AoE, and there is an incredible amount of effort going into making the various civs equal overall. There will still be favorite civs (currently mine is the French), and there will be endless debates about which civ is better on what map or under what starting conditions (obviously a civ whose bonus is 100 extra wood & food at the start is going to see his bonus amplified at Low Resources and minimized at High). And, of course, if you learn how to play a particular civ very well, you'll do better at that civ than when using an unfamiliar one. BUT ... we plan for no civ to be seen as automatically weaker on a conventional starting map under default conditions. - Sandy "Sandyman" Petersen, Ensemble Studios Designer - February 23, 1998