I think the trailer looks good and looks like it could be a fun movie. The first Avengers movie was good, fun and is one of few movies to pull of the extended third-act action scene well, balancing the various characters well.
This teaser does pretty much what it is supposed to do. Whet our appetites. We're not supposed to get much more from it than a slight peak at the final product. I think it looks very, very promising.
On the maligned scene of BW dropping from the Quinjet it does look a bit hokey, I admit, but the movie is still pretty far from release it could be an unfinished effects piece, could look better in the finished film.
Being a comic book movie doesn't mean it's devoid of meaning (or that it has to be). Heck, one of my biggest complaints about The Avengers (after how utterly hideous it looks) is that it's an explicitly authoritarian, borderline fascist film and completely ignores the implications of its heroes' actions because Whedon would rather have someone say something snarky and all's forgotten and he goes on playing with action figures.
I'd argue there's something of a conceit you have to accept when you go into certain types of movies. And the Marvel movies being comic book movies part of that conceit is that the characters get to fight imposing villains, cause damage in the process, and walk away from it when the day is saved. That they get to curtail rights and law to get to their mission.
Hell, "The Dark Knight" has Batman destroying the private property of civilians and violating a prisoner's rights (with aid from local law enforcement) in the name of saving a couple district attorneys. But, again, we accept it because it's a conceit of the genre and the character that someone gets to be a vigilante with a functional relationship with local law enforcement.
So, I don't think it's too fair a criticism against Avengers, or any comic book movie, to say the characters are doing things without consequences to their actions. That's like saying it's a bit silly for four men wearing nuclear-accelerators on their backs are jovial and quipping when they're on the cusp of the end of the world. The movie's in large part a comedy, so we accept that the characters are going to be comedic even when it's unreasonable to be so, we even ignore that the characters are consequence-free of their actions. They charge someone $5000 for their services even though they caused vastly more than that in damages in performing those services. They become local celebrities performing these services which, again, presumably cause a great deal of damage due to the unpredictability of their equipment.
So you have to measure what you expect from a film with what kind of film it is.
Avengers is a comic book movie set in a comic book universe where aliens, gods, and massive flying aircraft carries exist. A brilliant man can pretty much make a perpetual energy device in a cave from missile scraps and this device gives him near limitless powered flight. A cocktail of medicines can turn a 90lb asthmatic weakling into a taller, muscle-bound man who's at the peak of human capability. Exposure to radiation can cause a man to turn into a hulk, invulnerable, beast depending on his emotional state. (Rather than giving him severe cancer and him dying in a couple of days.) An archer and a woman with a couple of pistols are able to survive a battle with powerful aliens.
All stuff we have to accept for this type of movie so it's not too much further to accept when the job is done they get to just move along home and not worry about consequences.
If this happened in a movie with a realistic setting, say a crime or military drama, questioning it would be worth it.
But sometimes the genre a movie is in dictates the leeway it gets when it comes to questioning events in it. The Marvel movies are comic book movies so comic book rules get to apply. Heroes can get away with whatever they want because at the end of the day they end up saving civilization and the world.