Great move for Marvel, and interesting that they're not following the template of the EA/Star Wars deal with single-publisher rights.
My only concern is homogenization, that Marvel might take its videogames so seriously that it'll only let AAA projects that are huge in scope and character depth get through the system. It'll be awesome for the games it delivers, but the games that don't get through such a system could possibly have been the games that would speak to me as a gamer.
Like if their approach is "epic" games ala the Marvel Cinematic Universe, something as story-devoid and canon-breaking as Marvel vs Capcom might not fit that scope (and any time fighting games try to hew to a larger story, the fun gets crowded on.) Having two different Spider-Man play concepts such as Spider-Man 2 and Ultimate Spider-Man might confuse the brand. Would something family-oriented or multiplayer-focused like LEGO Avengers or Marvel Super Hero Squad still fit? Will every game be a third-person hero adventure (as that's often the most "epic" way to show off a character,) or will varied gameplay experiences be as important to the initiative as epic production quality? Does a portable system like 3DS count when they talk about "epic"? Is a racing game "epic"? How many games have to go through the system before something wide-ranging like Ultimate Alliance can happen (do we have to establish every character before putting them in a team-up game?), and if Sony has Spider-Man and say Microsoft has Hulk some other companies have different characters, does Marvel have the clout to do a character-spanning game using platform-exclusive characters in some other publisher's product?
..But for the most part, I'm psyched for this deal! I'm excited for the level of quality this first title is indicating the whole Marvel Games line might carry, and I'm hopeful that my fears will be allayed through gameplay concepts that push the idea of "epic" in all directions.