If Street Fighter is so lame why is it the most played Arcade Fighter in the world? It DOES have a story. Each character has a story. I really never payed attention to most of them aside from Guile (Because that's who I play as). Guile's story is that he joined the Fighting circuit to go against M. Bison (or Vega, in Japan) because he killed his comrade Charlie in a previous time, You can play as Charlie in the Alpha games (which take place before the original Street Fighters).
MvC actually has a storyline too. Not that I actually remember what it was, but at least it's got one. It's storyline is somewhat similar to the first Super Smash Brothers storyline. One big baddie gets a bunch of people together fighting and the winner has to fight the big baddie to save the world.
They also made Namco/Capcom Cross over, which is an RPG. That too has a storyline. Honestly I don't see how the Mortal Kombat universe is going to fit into DC…not that Marvel did, but the game was pulled off with amazing results. MvC is one of the best fighters out there. Mortal Kombat is one of the worst. I do admit it, I love the game, but the fighting sucks! From an Arcade Fighters point of view it's absolutely terrible. All the MK's have been. Laggy response time, cheap moves, all that crap.
From an Arcade Fighters standpoint; MK vs DC looks completely and utterly terrible.