You may be pleasantly surprised. I realize that "comic book" movies is more then just the Marvel and DC movies, but they are the bulk of the popular ones, that I suspect you are worried about. If you look at the movies in for the 2000's there are 3/6 DC movies, and 3/19 Marvel movies*. Granted most of the MCU movies are in 2010's and those are generally the best of the marvel movies.
*based on list provided by:
http://en.wikipedia.org/wiki/List_of...d_on_DC_Comics
http://en.wikipedia.org/wiki/List_of..._Marvel_Comics
There will be 34 Marvel movies in the 2010's and 10 DC.
So far it has seemed like a theme to only nominate one movie from a series (the LOTR and 2 batman movies are notable exceptions). Maybe that will continue.
Yeah, it could a lot, maybe 15-25 is my prediction.