That superhero films cross over into other genres isn't really that unusual, is it? When was the last time anyone here saw a Hollywood film that could be distinctly referred to in the terms of a single genre?
It seems pretty clear to me that the superhero film has its own iconography and narrative conventions, and has lasted long enough in Hollywood, that it should be considered its own genre. Certainly we're witnessing a current cycle of this type of film now, but it would not at all be unreasonable to compare Green Lantern (2011) with, say, Superman (1978) or Batman (1966).
It seems pretty clear to me that the superhero film has its own iconography and narrative conventions, and has lasted long enough in Hollywood, that it should be considered its own genre. Certainly we're witnessing a current cycle of this type of film now, but it would not at all be unreasonable to compare Green Lantern (2011) with, say, Superman (1978) or Batman (1966).