I guess if you are using that loose of a definition, then it works. Personally, I need the belief aspect. If people didn't worship particular gods or believe that a hero told about actually existed, then it is just a fairy tale, not mythology. However, I know that we do mimic what made myth stories great in our movies.
George Lucas is a Joseph Campbell disciple. He follows the Hero's Quest formula that Campbell devised after studying heroes of all cultures. There is a great site that puts the Hero's Quest in a simple chart and shows how Star Wars and The Matrix. You can find that here: http://www.moongadget.com/origins/myth.html. It is a fantastic introduction to the monomyth idea (all cultures are connected by the similarities in their myths).
Take the Harry Potter stories for example. Not only does he follow the Hero's Quest, but there are so many mythical allusions in there. even if the average reader doesn't recognize all of these, he/she is still enchanted (bad pun) by them.
Back to the editorial, the author goes on to point out how movie superheroes teach us lessons (which, once again, is the author's definition of mythology). He or she points out that Batman teaches us not to become the enemy we fight, Superman shows core values, and X-Men show us not to hate others because we don't understand them.
Great, but these are life lessons, not mythology. Mythology is wrapped in our heroes, but not just because they deal with these lessons. Sometimes it is about fate. Why does Hercules do all those wondrous deeds? Fate (in the form of Hera) played all kinds of nasty tricks on him, resulting in the death of his family. Same goes for Batman. Fate plays a part in the death of his parents, thus shaping the way for him to do his deeds. Why is Odysseus tormented? Because of the choices he makes. Same goes for Spider-Man.
But mythic heroes do not always teach us life lessons. Achilles is glorified because he wanted to be glorified. He fought well (I struggle to say bravely since how brave is it to fight when one can't be hurt). Jason is scum of the earth.
What makes myth is more than a life lesson. That is a fable or fairy tale. It is us and belief. We see heroes with powers and bravery beyond us, but they are flawed like us. They teach us to rise above where we are (but not too high as in Bellerophon's case) and to be nice to others (just in case Zeus is slumming again). They also teach us that some things just happen. These things are unavoidable. Every oracle story teaches us this. Oedipus teaches that. The true test of a hero is how he reacts.
I guess what all my rambling comes to is what is my definition of mythology. I have always defined it as a what used to be believed by a culture but is now no longer. I looked it up in the dictionary (we English teachers like to do that sort of thing). It told me mythology was a collection or study of myths. O.K. I should have known that one was coming. I looked up myth. Alpha Dictionary says it is, "a traditional story accepted as history; serves to explain the world view of a people." Encarta says, "a traditional story about heroes or supernatural beings, often attempting to explain the origins of natural phenomena or aspects of human behavior." That's not bad. I would really like to hear your viewpoint on what a myth is.
Doubtfully I cleared up anything, but at least you got a great web site for the Hero's Quest. By the way, the picture at the top is of the Spider-Mobile. It was in a very bad Spider-Man story arc back in the 1970s. This also teaches us a lesson. The good old days were not always what we remember.The editorial that sparked this nonsense can be found at http://www.star-ecentral.com/news/story.asp?file=/2008/5/12/movies/21194060&sec=movies