Blue Marvel would be nice, but far from it being a certainty that he's going to play a character, I'm thinking it's far more certain that he won't play a character. There's no way Marvel's going to pay him his fee across multiple films. This IS Marvel, after all, which has already demonstrated they're horrific cheapskates when it comes to paying the people they employ. And putting him into an Avengers movie would be right out, as they already have the fees for all the other Avengers, RDJ, Hemsworth, Evans, and so on to pay out. So yeah, I'm thinking Will Smith will likely never be cast in any role, not even if he wants one, due to his fees. Even if he's willing to drop his fee to do a movie, well, once again, we're talking multiple movies. He may be willing to drop his fee for one movie, but a series of them? Not going to happen.