The business downside, I think, is in watering down your assorted brands, to the point where they all become one large amorphous blob of a brand, and much of what everybody likes about them has been subsumed. And the huge upside that you’re talking about is only huge depending on the form that such stories would take. None of this sounds like the sort of thing that would be done in comics first, because there’s just not enough money involved there to make the endeavor worthwhile. In a videogame maybe, like Disney’s Infinity–but even there you have to be careful what and how you mix and match. Marvel works because it’s Marvel, and done by the people who understand Marvel, and Star Wars works because it’s Star Wars and done by the people who understand Star Wars. Mixing the two isn’t necessarily a comfortable fit–though I tend to think that the Marvel Universe could integrate Star Wars better than Star Wars could integrate elements of the Marvel U.