HP trounces DC Comics in its fan base size, no denying that. Its just that next year Marvel has the Avengers from their own studio, a new Spidey franchise and loads more ahead. Marvel more often than not has proved the superhero movie is profitable and works when done right. Warners just so happens to own rights to every single DC character. For every flop like GL there could be an epic Flash or WW film. Its not so much about replacing HP, but more about taking that queue from Marvel. Whether Marvel is its own independent studio or not, its the concept of churning out more films from the depths of their roster.