I've heard that both companies have discussed it with each other but it just wouldn't work. For one thing as Hulk Power suggested, they are two different "universes" so to speak so you have differences in power and scale.
In fighting games you usually have roughly three "classes", your fast characters, your powerhouse characters and your all rounders. As such, each Marvel and DC character would have to be modified to conform to this. This leads to...
Problem 1: by who's standard do you rank them? Who decides if Spidey would be and all rounder or a speed freak? He's not as fast as the Flash but he is a lot faster than Batman. Should the Hulk do is much damage as someone like Darkseid? Such discussion leads to...
Problem 2: Fanboy conflict. If this game saw the light of day, how many posts would we see that said something like "OMG the Human Torch's fireball should own SupermanZ laser eye attack!!!" Such bickering would probably end up taking the focus away from whether the game was actually any good or not.
It will be a cold day in hell before this game sees the light of day.
Gender: Male Location: Right below you tossing gernades;
I wouldn't mind. I mean, MvC2 wasn't that balanced overall yet it still was fun to play and was the most competitive 2D fighting game in the US (as an example, Sentinel was the best character in the game compared to characters like Magneto or Thanos who would DESTROY it in the comics). You guys are thinking too much in a comic book sense in my opinion. If they were to make it by Capcom (who unfortunately do not have the license to make the Marvel vs. games anymore), knowing their previous successes with their games, I think it would be great as long as people don't think in a comic book state of mind.
Gender: Male Location: Welfare Kingdom of California
They can make a DC and Marvel Crossover Comic book but a Video game is a long shot. Personally, I go with DC as the winner. Marvel characters are overdone. DC characters are better.
[SPOILER - highlight to read]: And that comment above is an example of fanboyism
wild dancer i am not a fanboy of anything i just like things and just the prospect of a marvel vs dc crossover is exciting as a fan of supereros i have been trying to get hold of Marvel vs DC crossover material for over 4 years and i cant there isnt any comic shops were i live and father dont have a credit card i have always wanted to see what would happen if the two universes collided so i ask you to reconsider befor you call someone a fanboy please