I honestly can't say I'm hugely disappointed by Tintin's sputtering at the box office; it's not about the movie's quality, it's that we were almost away from Hollywood believing that fully mo-cap CG movies are a good idea, and this movie threatened to pull us back in like Michael Corleone. Granted, the success of overseas is a thing, but hopefully people will write it off as the brand name and otherwise kill mo-cap as a technique.
As for the box office returns, this was a bit of a lackluster year from a blockbuster franchise perspective--even Harry Potter Part 7 Part 2 had a bit of a pall over it based on what a snooze Part 7 Part 1 was--and there was a lack of exciting new word-of-mouth movies, which is always a major factor in the box office that Hollywood is increasingly ignoring. (Bridesmaids proves that it's still important, however.) There's also the lousy economy. As I've said before, you have to look at the box office for a given year or season holistically, not on a movie-by-movie basis. 1999 was a huge summer for box office because people were excited about Phantom Menace, but there were some other interesting offerings, and people were generally excited about going to the movies. This past year was the opposite--there was nothing for people in general to get excited about. There are fans of various franchises who went out to see Transformers and Twilight, but those tend to reach an established audience and leave everyone else behind. You need at least one breakthrough blockbuster to elevate everything around it, and that didn't happen this past year.
I think there'll be a big bounce-back in 2012, though. There are some potential new franchises like The Hunger Games, the Avengers feels like something new and special, and the franchises that are returning--The Hobbit, Skyfall, Prometheus, The Dark Knight Rises, possibly even Men in Black 3--actually feel *big* and important instead of "well, here's another Harry Potter movie."