So my picks for weak civs are Britain and Portugal. Britain and Portugal are brother/sister civs. They seem to play alot alike, with a decent military and a strong economy in late game.
Britain- 20 manors=20 more villagers
Portugal- 2 tcs early= more villagers
That is nice and all, but I am not sure they can get late game. It seems to me that the opposition can go up early and then push them off of the key resource to their eco. No wood for Britain will starve them into a slow death. No fast food (hunt) for Portugal will make the extra TC irrelevant because they can't afford to que settlers in two TC's and make any sort of military.
Plus, if every one knows that Portugal gets a free TC to start the 2nd age, why dont they just go up early and ship some melee infanty over. You just hang out around the town until they advance, then go in and take out the wagon.
My pick for the strong civs will be Spain and Russia. Spain is underrated and will be underplayed after we all spent a month on them with the demo. But they are good, they are flexible enough to rush, turtle or boom, and their military lines are great (who misses the grenadier, when you can mass pikes and then build cannons?). Russia looks good for their rush, but the 3 settlers at a shot boom could be amazing if they can flood to get map control and hunt hard.
Of course this is all guesswork for another week or so.