i think there will always be an audience for comic book movies because the comics themselves have always had a big following. with the improvements and changes to technology, characters can now do a lot more on screen than ever before. it's somewhat reminiscent of what george lucas said about the star wars movies and the technology finally catching up to his ideas.
the issue is now the story lines available for these movies (there will be hits and misses) as well as the sheer number of how many films are out there. the market seems saturated to me, and i think the comment about the boy band explosion of the 90s is a fair one for comparison. as long as this genre of movies continues to make money, expect to see them continue to be made. our choice for more or less of these movies is to vote with out wallets.
i have no plans to see guardians of the galaxy, but i'll probably go see avengers 2.