First of all, despite conventional wisdom, Batman Begins isn't nearly as dark and somber as you've been told. In the run-up to its release, Chris Nolan mentioned that he was crafting an action-adventure appropriate for twelve-year old boys, and that's pretty much how it played. It's quite terrific, and it tells its story with an uncommon intelligence and empathy that makes it function as truly all-ages entertainment. But in terms of onscreen violence and gloomy characters/settings, Batman Begins is really not that much worse than a conventional comic book film. The only moment of violence that truly disturbs is the onscreen murder of Bruce's parents, mostly because of how low-key and frighteningly plausible it is. The rest of the violence consists of occasionally brutal beatings administered by Batman and the occasional bloodless shooting death (for what it's worth, it actually has a lower onscreen body count than Batman, Batman Forever, and Batman & Robin). There are moments of PG-13 intensity and arguably the Scarecrow-enhanced menaces are a little scary for younger kids. But Batman Begins is at its core a robust and energetic action drama that thrives on the optimistic idea that a few morally decent people (Wayne, Dawes, and Gordon) can make a real positive difference. I would argue that The Dark Knight is indeed gloomy and 'dark' because of how brutally it undercuts that somewhat simplistic ideology. But that merely makes it one of several blockbuster sequels (The Matrix Reloaded, Pirates of the Caribbean: Dead Man's Chest, The Empire Strikes Back, etc) that thrive on exposing the dark underbelly of the somewhat simple hero's journey from its respective predecessor. Aside from the usual 'this situation is more complicated and morally gray than I first realized' arc, the one element that sticks out in The Dark Knight is its climax, where regular civilians are tasked with choosing whether or not to murder other civilians in order to save their own lives and the lives of their family members. Whenever my kids eventually see the movie, *that's* the part I'm going to have the hardest time discussing.
And let's examine for a moment the various blockbusters that followed in the path of Batman Begins and The Dark Knight. Strictly in terms of comic book adaptations, the only post-Dark Knight comic book movie that qualifies as 'dark' would be X-Men Origins: Wolverine, which was always going to go that route. The Punisher: War Zone is obscenely violent, but it's more of a 'fun' and brightly-lit gore cartoon than a serious-minded drama. Iron Man 2 takes a character arc from Batman Returns (I must confront and destroy villains that represent that which I might become!) with the narrative structure and kid-friendly tone of Batman Forever. Watchmen was going to happen some day no matter what, and its first trailer actually debuted with The Dark Knight. You could argue that Spider-Man 3 and Superman Returns, which came out after Batman Begins, were darker and more introspectively somber than the series norm, but neither can blame Nolan's success for the tone. Superman Returns was in production as Batman Begins was entering theaters while Spider-Man 3's 'the darkness within' subplot was due to Marvel forcing Sam Raimi to include fan-favorite Venom. None of the several comic book films of summer 2011 were 'dark', in fact Thor and Captain America went out of their way to embrace the gee-whiz adventure aspect of comic book storytelling (Thor is so kid-friendly I'd consider showing it to my four-year old if I thought she'd get anything out of it). X-Men: First Class is no more or less morose than the darker portions of Bryan Singer and Brett Ratner's respective X-Men pictures. X-Men: First Class does do the same thing right that Nolan did, which is tell a genre story (in this case, a 1960s Cold War spy caper) within the confines of an established comic universe, but that's not what everyone is complaining about.
I'd argue that of the various comic book films over the last seven years, only Green Lantern and Iron Man seem unduly influenced by the Nolan Batman pictures. Martin Campbell attempts to balance larger-than-life outer-space heroics with character introspection and a horror film sensibility, to very very mixed results. The irony of course is that Green Lantern was riffing on Iron Man which in turn was riffing on Batman Begins. Jon Favreau's Iron Man, released just two months before The Dark Knight, was clearly playing from the Batman Begins playbook (its been jokingly argued that they are the exact same movie). It sets its comic book tale in a very realistic modern-day setting and has its protagonist grapple with very real social and political issues as he takes his heroic journey. Hell, I'd argue that the second-act climax, where Iron Man saves refugees and takes revenge on his former captors, is the most unpleasantly violent sequence I've ever seen in a PG-13 comic book film (not only does Iron Man kill countless people, but the scenes proceeding his arrival show civilian murders-galore and entire families being massacred just offscreen) and worse than any of The Joker's antics in The Dark Knight.
We've heard and read the dark/gritty cliche tossed around to explain The Amazing Spider-Man, but going somewhat darker and more realistic was the only place left to take that series after the gee-whiz 1960s-style adventure of the Sam Raimi trilogy. So among the various comic book movies that have been released since 2005, really only Green Lantern and Iron Man can be considered 'inspired' by the Nolan Batman films, and both of them take more from Batman Begins than The Dark Knight. Even looking at general summer blockbusters over the last few years, the big movies were the bright and cheerful Star Trek, the often-campy Transformers trilogy (which went uber-violent in the last hour of Dark of the Moon, but I digress), the sweepingly allegorical Avatar, the brainy Inception (which due to its dream motif had almost no real violence), the PG-rated cotton-candy colored Alice In Wonderland, and the admittedly dark and violent literary franchises that are Twilight, The Hunger Games, and Harry Potter. There is no real evidence, aside from an unseen Amazing Spider-Man and promises that Man of Steel will be 'real' or 'down to Earth' that Nolan's Batman films, especially The Dark Knight, have influenced the modern comic book film or even the modern blockbuster when it comes to tone, violence, or intensity. The comic book films over the last few years have been bright, colorful, larger-than-life, and often out-of-this-world. And looking at the non-comic book blockbusters, they generally have been too. Four years after The Dark Knight, the modern would-be blockbuster still makes a concerted effort to be *fun*.