In a phone conversation with Empire Magazine, director James Gunn talked about his plans for Guardians of the Galaxy 2 (slated for July 27, 2016) and the issues of Peter Quill's father.
"I've got the basic story for the sequel worked out. I've thought a lot about where these characters are going and where they came from, things we've gotta find out. There has been a lot of world building we've done that we get to play with in the second movie. There have been a lot of documents passed around about who Peter Quill's father is, and things like that, between a select two or three of us. That's been part of the plan since the beginning, that's something I had to work out and I worked it out before we shot the screenplay. We wanted to make sure Yondu's place in everything made sense and it does, so it's all very specific stuff."
The most important thing Gunn said seemed to be this:
"It's definitely not the character who it is in the comics, I'll say that much."
As for how much Gunn of what they did with the first movie and will be doing with the second movie was dictated by the studio and how much he was able to bring in:
"I like being able to create a bad guy. I'm very lucky in that I came into the Marvel Universe and I didn't have too many rules set down for me. I came from a place of creation. I had a few things I needed to link up to, a few points of reality that our universe had to link up to, like they were dealing with the Infinity Stones, that the Aether is an Infinity Stone, so I had to link up to those things, but they were very few and far between. For the most part I got to create things, like the Bible of the Infinity Stones – where they came from, what they are, that was something I got to invent."
"How does Thanos talk? Who is he? What does he do? I got to invent that, that was all really fun for me. Someone else will have to be somewhat beholden to those things later down the line. For me, it was all pretty much fun. I will say that I do not feel beholden to having to use Thanos in Guardians 2. He will show up if he helps our story and he will not show up at all if he is not. Thanos is not the most important thing in Guardians 2, that's for damn sure. There's the Guardians themselves and other threats the Guardians are going to be facing that are not Thanos."