The lights are on
This would be epic. To satisfy both companies, both companies could create their own version of the game like Street Fighter X Tekken was supposed to be. That way you'd have Marvel X DC and DC X Marvel. The fights would be pretty epic, but alas, I don't think it will ever happen. When it comes to this project, the creative differences would be extremely huge. DC would want Superman to be such-and-such powerful and taller than Thor, Marvel would want Iron Man to have more gadgets than Batman, Flash faster than Quicksilver, etc. It's the same problems the Wreck-It-Ralph crew had making their movie. Who knows, maybe they'll put aside their differences one day and we'll get the game we deserve, but for now, we just have to deal with the fan speculation that we need.