Guardians of the Galaxy Vol. 2 will not only bring back a huge chunk of the cast roster of the 2014 original movie, it will also introduce Hollywood A-listers Kurt Russell and Sylvester Stallone. Russell will portray Ego the Living Planet, who is Star-Lord’s father. The identity of Stallone's character is yet to disclosed, although we do know that he’s a Nova Corps member who’s "very important to the Marvel Universe".
In a recent interview with Fandango, James Gunn gave away no significant details on either character. He did make it clear that Marvel Studios had big plans for both of them in the future, confirming that they’ll appear in the Marvel Cinematic Universe again:
This is definitely not a one-off [for them]. They're both characters that we've taken a lot of time to develop, and they're a big part of the MCU now.
Chris Pratt recently stated that the May 5, 2017 release will win "every movie award AND about 39 Olympic gold medals". Gunn was more cautious, but he did say that Michael Rooker deserved an Academy Award nomination for his performance as Yondu in Guardians of the Galaxy Vol. 2:
I will say this about Michael Rooker, and this is no joke. He deserves an Academy Award nomination for this movie. He is amazing in the film, and he's blowing people away. It's such a deep, honest, and truthful performance from him. Who would've ever thought that Rooker's real lifetime-achievement role would be with a guy who's painted blue and has a big fin on top of his head, but it is. He's just amazing.