Official plot synopsis for Black Panther:
"Black Panther follows T’Challa who, after the events of Captain America: Civil War, returns home to the isolated, technologically advanced African nation of Wakanda to take his place as King. However, when an old enemy reappears on the radar, T’Challa’s mettle as King and Black Panther is tested when he is drawn into a conflict that puts the entire fate of Wakanda and the world at risk."
Andy Serkis is also confirmed as making an appearance, reprising Ulysses Klaw from Avengers: Age of Ultron.
http://m.ign.com/articles/2017/01/26/black-panther-full-cast-and-official-synopsis-revealed?read
I've found it weird how we've had oodles of casting announcements for Black Panther, yet it hadn't been until now that Any Serkis, one of the guys everyone figured would be a given, has finally been announced. Oh well. I guess it doesn't matter. I'm glad he is in it at least. Maybe this might signify though that he won't actually play the main villain or even that big of part in things.