Guardians of the Galaxy dropped a couple of intriguing tidbits about Peter Quill/Star-Lord's (Chris Pratt) long-absent father over the course of the movie. Peter's mother referred to him as an "angelic" figure, whereas Yondu (Michael Rooker) held something of a lesser opinion of him - that he was a "jackass," to be exact. The film also revealed that Peter's father was, in fact, not human and a member of some ancient extraterrestrial race instead, shortly before wrapping up. It's only fitting then that one of the narrative through-lines for Guardians of the Galaxy Vol. 2 involves the search for Star-Lord's missing dad.
Guardians of the Galaxy 1 & 2 writer/director James Gunn has long maintained that not only would Star-Lord's dad be different from the character in the world of Marvel Comics (Jason of Spartax), but that his identity would be revealed well ahead of the sequel's release - which it has been. During the Guardians of the Galaxy Vol. 2 trailer shown at San Diego Comic-Con 2016, it was revealed that Star-Lord's dad is Ego The Living Planet; who, as his name implies, is a sentient planet that can present itself in the form of a human - one that looks a lot like acting legend Kurt Russell, it turns out.
Gunn, when interviewed by Empire, revealed that it was actually Pratt and not him who suggested the idea of casting Russell as Ego in the Guardians of the Galaxy sequel:
“He was actually not in my head initially, but one day Chris suggested him, and I would have been really disappointed if he’d said no. Hey, if you have to cast anything, Kurt’s a pretty good way to go.”
As others have noted, the casting of ultimate cool guy actor Russell as Star-Lord's dad is, indeed, smart casting on multiple levels. For starters, the implication in the first Guardians of the Galaxy is that Peter's father is something of a cool player in his own right; hence the adoration from Peter's mother and the annoyance (or maybe it's jealousy?) expressed by Yondu towards him.
Beyond that - seeing as Star-Lord himself is something of a wannabe rock star in the vein of a 1980s action movie hero, it's only fitting that the actor who's playing the character's father is, in fact, a real-life '80s icon (thanks to his roles in such films as The Thing, Escape from New York, Big Trouble in Little China, and so forth).
Star-Lord, of course, has been searching for his dad for a long time when Guardians of the Galaxy Vol. 2 picks up - and as Pratt told Empire, that has not only impacted his expectations about Ego, but also what their relationship will be like after they've actually met:
"You’re going to see these characters having to endure the realities of being in a family. You’re talking about a guy who’s been longing to know who his father is for a long time. He’ll discover if that person lives up to the expectations he has in his head.”
Gunn has maintained from pretty much the beginning that Guardians of the Galaxy Vol. 2 is "a story about fathers," so it stands to reason that the relationship between Star-Lord and Ego will be explored in a fair amount of depth over the course of the film - as will the "daddy issues" held by other characters in the film (see Gamora (Zoe Saldana), Nebula (Karen Gillan) and their emotional baggage from having Thanos as their "father").
However, lest anyone think that Ego will be all coolness (as well as a sizable penis, as he tells Drax (Dave Bautista) in the film's Comic-Con trailer) and no heart, Gunn has teased otherwise; saying that when it comes to Ego in the sequel, "being a cosmic being, alone for eons, is perhaps even more lonely than being the universe’s sole talking raccoon."
Doctor Strange opens November 4, 2016; Guardians of the Galaxy Vol. 2 – May 5, 2017; Spider-Man: Homecoming– July 7, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; Avengers: Infinity War – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel– March 8, 2019; Avengers 4 – May 3, 2019; and as-yet untitled Marvel movies on July 12, 2019, and on May 1, July 10, and November 6 in 2020.