I'm not going to say that 'Thor 2' was the best of the Marvel movies to date. The plot is very generic fantasy in its tropes and basic structure (ancient enemy, ultimate weapon that's buried instead of destroyed, said enemy returns looking for its old weapon which is now in the hands of a single Hobbit...er, Natalie Portman...) and while I don't think that Malekith was quite as under-baked as some of the reviewers, he was kind of a waste of Christopher Eccleston. (Seriously. You get a guy like Eccleston, you give him some good speeches. Malekith didn't make speeches, because he was fully convinced that there was no need to justify his actions. I'm okay with that--when you've decided that the universe is a mistake and needs to be erased, there's no real point in explaining that to its inhabitants. But it means that Eccleston doesn't talk much, and he's an actor who's good at giving speeches. Just think of his scenes in '28 Days Later', which are all about self-justification, and you'll agree.
But what I did love about 'Thor 2' was its sense of playfulness, its understanding that there's something just a little bit goofy about a series of films whose hero is a big doofy guy who thinks that "hit things with a hammer until they stop moving" is an actual strategy. Thor wanders through the world like this big, glorious, crazy chunk of four-color simplicity, and some of the best gags involve the ways that he interacts with mundane life. (The symbolic heart of the movie is the tiny little gesture he makes when he comes into Jane Foster's apartment and hangs Mjolnir up on the coat rack.)
This sense of fun infuses the whole movie. The big final battle is as much farce as it is drama; Thor and Malekith chase each other through dimension-spanning portals in a fight that owes as much to Looney Tunes and Benny Hill as it does to Lord of the Rings. (Oh, sorry, there's something of a spoiler there...although if it really surprises you that there's a big fight at the end between Thor and Malekith, I suspect you're not really the film's target audience. Although you'll probably be blown away with shock when Thor wins--oh, sorry, more spoilers there.)
The point is, this is a film that's not afraid to lose a little dignity to gain a lot of charm...and it vividly contrasts another problem with comics these days. (On top of all the other ones I mentioned in all my other posts.) Marvel is absolutely terrified, at least in its comics, of looking silly.
I think the root of this is that Marvel has, for a long time, been aiming its publications at kids. And kids love to laugh as much as they love to be frightened, to be excited, and to be grossed out at mushy stuff. When the Hulk talked in his big, dumb, "Hulk smash puny humans! Bird-nose shouts too much at Hulk!" patois, it was meant to seem silly and goofy, because that helped humanize the Hulk and make him less of a monster. When Daredevil fought villains like the Leap-Frog and Stilt-Man, you were not supposed to see them as necessarily a figure of utter terror.
But nowadays, Marvel comics are written by adults for adults. Or, more accurately, they're written by adults who hate having to explain to people that comics aren't just for kids anymore, for adults who hate having to explain to people that comics aren't just for kids anymore. They have a pathological fear and loathing of anything that might smack as "childlike", because they're afraid that some non-comics fan will spot that one panel as their first exposure to comics since they were five, and they'll look derisively at the fan and say, "You actually read this stuff?" Or worse, "You actually write this stuff?"
So humor has been banished. Everything is, if not grim and brutal, at the very least to be taken absolutely SERIOUSLY. Everyone is serious about everything they do, and every villain is a serious threat to humanity that must be fought by serious heroes being seriously serious. The only humor still allowed is to make fun of how silly things used to be; everyone can mock the way that the Hulk used to talk, but nobody seems to understand that it was a joke. Even when we're not getting on-panel disembowelings and villains raping women to show how evil they are and the other trappings of arrested adolescence, the pathological avoidance of anything that might be considered "fun" is almost total. (Maybe this is why Squirrel Girl and Deadpool are such fan favorites. They actually get to be...gasp...silly.)
So again, I find myself gravitating to the movies, where Thor has to take the London Underground to get back to his battle for the sake of the universe, and Jane Foster's best friend calls his hammer "Mew-Mew". Because it is silly, it remembers that the whole idea of superheroes are wonderfully and gloriously silly, and it understands that it's not something to apologize for. It's something to embrace. Because, in the immortal words of Terrance Dicks, "What's the point of growing up if you can't be childish sometimes?"