I also saw the trailer for Captain America! I like the look of it. Since Cap is my favorite Marvel character, I was hoping this movie would be good. Looks like it, though of course I'll have to see it first to know for sure. I'm a sucker for World War II-era stories, anyway. :)
I love the parallels between DC's and Marvel's Trinities: Superman and Captain America are the centerpieces, the ultimate heroes, the emobodiment of Truth and Justice, and especially in Cap's case, the American way. :) While Cap has no powers and Superman is the most powerful, Cap is a super-soldier due to the serum he received, and is the heart and soul of the Avengers, as Clark is with the JLA.
Batman and Iron Man: two poor little rich kids who grew up pretty much without their biological parents (Bruce's were murdered, and Tony's were there but absent), who are insanely rich, who use that money to fund their gadgets to fight crime. Also both are intensely interested in science. Interestingly, while Bruce is not an alcoholic like Tony is, he could easily be if he didn't have his iron discipline. Both have butlers important to them (and more than butlers), Alfred and Jarvis, though the latter is mechanical in the movies. :)
Wonder Woman and Thor: Goddess and God, literally! :) Both spring from their respective Greek and Norse mythologies and wield powers and weapons from the Gods (the Golden Lasso, Mjolnir) and grew up in Paradise-like settings. Both leave their homes to live amongst mortals and defend them with their unique powers.
Marvel is certainly far ahead of DC in their live-action movie department. All three of their Trinity will have major motion pictures which will dovetail to an Avengers movie, and DC? They'll have the next Batman flick, a dubious Superman one, and nothing for Wonder Woman (who's never had any at all in this realm). The JLA? A dead project. Meh.