Honestly, Beyonce starring in Black Panther alongside Chadwick Boseman would be very smart. That's gonna be a huge movie for Marvel (to bring a different type of feel to their franchise), but I don't think Chadwick is BIG enough to sell it by himself. And you know they don't want to have the first huge-budget black superhero movie flopping.
There's Monica Lynne, who in the comics, is a SINGER who saved the Black Panther from drowning after being bested by Killmonger. His longest love interest, whom he pledged eternal devotion towards.
There's also Storm, Ororo Munroe, who's actually Black Panther's wife...
Also the movie doesn't release until 2018, so this could be possible...! Def expecting Beyonce, Kerry Washington, Gugu Mbatha-Raw names to be thrown around for these