What struck me most about the trailer (apart from the most awesome Winter Soldier and him going hand to hand against Cap) is the morality displayed in the trailer (and hopefully in the movie).
I'm not a big Cap fan way back when i read comics on a regular basis but he always embodied a simple, uncompromising black and white view of the world. He knew what's wrong and he didn't make concessions or soften it up around the edges if "times demanded different actions".
He just was this fixed point where you could measure yourself against to see how far you have strayed. Some may call that simplistic but it's also the greatness of the character who won't budge under any circumstances and who will face every consequence but he will remain true to himself.
I guess if he were real and live in the post 9/11 world he would have some choice words on Guantanamo, Abu Ghraib, the "Patriot Act", wiretapping etc (heck.. he even quit the job at one point in the comics out of protest because he couldn't support the government's actions).
If that translates well into the movie i'll be one really satisfied customer, if not at least i'll get some cool scenes and 'splosions for two hours.