A Scarlet Witch movie? FAIL. This is a worse idea than Guardians of the Galaxy and Ant-Man.

A Black Widow movie? FAIL. None of supporting cast, such as BW, Hawkeye, Falcon, or War Machine should have their own movies.

Iron Man 4, Thor 3, and Cap 3 are surefire bets, as is a Hulk 2 at some point with Ruffalo (although, I consider him more supporting at this point, and shouldn't have another one excpet supporting appearances and Avengers movies).

Black Panther NEEDS to happen, Thor worked for crying out loud, Blade 1 and 2 worked. As for actors, dude from 42 would work, and Chiwetol would be AWESOME in this role. I'd love to see Michael Jai White b/c he's a badass, but he doesn't have the acting chops to pull it off. This could and should work, just a shame there's a cloud hanging over such a cool and promising character. Guardians? Ant-Man? Dr. Strange? C'mon Marvel.

Also, if these reports of them low balling the actors for the next Avengers movie is true, they are already shooting themselves in the foot for the future.