Ever since they did the Marvel/DC crossover series years ago, I've been itching to see it brought to the screen. I think the concept definitely has potential. It would appeal to fans of both super-teams, and there's bound to be great interaction between the counterpart heroes of each universe (i.e. Batman & Ironman, Superman & Thor), as well as the villains (I can very well imagine Lex Luthor and Loki forging an alliance to conquer both teams... while planning to stab each other in the back.
Unlike the past cross-overs from other films, were they have crammed so much into one film like Freddy v Jason and AVP.....well AVP tried to cram lots into 2 films and both ended up being shit. If the JL and Avengers was to be done it should be done as one long trilogy similar to Lord of the rings and Matrix.
Having the trilogy means would mean Screen time for all the characters would be a lot easier then trying to get 10 of our favourite supers into a 140 min film, origins could be brought in a bit better.
The marketing would be so easy for the film as well, The internet from Rival Marvel and DC fans would be bigger then ever.
Once again there is no way in hell that this would ever be done which is Sad as its a win win for all involved, but let us hope.
What are your thoughts on seeing the two brands on the big screen? What story line would they go for?