The internet show Nextnik presents a case of skepticism for the new phenomenon of "motion comics:"
I had not even thought of this problem, but have to agree that it is worrisome. I read alot of comic books as a child, and they spurned my interest in the written word which has ballooned into my producing what you're reading now. The book I am writing now is a sort of ode to what comic books and science fiction provided my mind.
Nevertheless, I wouldn't worry too much. I still see children's books for sale and cartoons, which encouraged no reading whatsoever, have been made out of comic books for a long time. Alot of people my exact same age don't seem to show any interest whatsoever in reading or writing (one girl literally told me once "I don't read") and that is very sad and unfortunate, but Barnes and Noble is still a healthy business in my hometown and throughout the country. The written word has its place and will (hopefully) never be replaced.
Meanwhile, check out some of the motion comics being produced, such as Superman: Red Son: