It’s almost certain that there will be elements of the comics in Avengers: Infinity War. There are already some pretty strong rumours floating around about Death taking a big part in the film, and you can draw your own conclusions there.
But just how much of the story will come from the source? Speaking to Slashfilm, Marvel’s Kevin Feige explained that things might diverage a fair bit, he explained:
In the immediate future, being the movies, we’ve announced… I think those with knowledge of the comics may expect things that will not be happening in the movies. Those who don’t know what has happened in the comics will be shocked at what we do.
But yeah, once that Gauntlet is on, as the poster of Doctor Strange says, “the impossibilities are endless.” How do you fight that? How can you defeat that? So we play into all of that. We play into all that stuff. I don’t know that we’ll get into Earth 1 thru 616 in any one moment anytime soon.
The Marvel movies are actually pretty good at taking elements of different stories and weaving them together I reckon, so I really hope the teams in charge have figured out what to keep and what to drop for the right reasons.