With a reply to a fan question on Facebook, filmmaker James Gunn seems to have given some insight into his particular interests as a comic book fan.
Asked whether he would like to make a DC Comics adaptation or if he were precluded from doing so, Gunn responded, "I am precluded. Would have loved to have done Shazam."
This presumably means he's precluded from doing so by terms of his contract with Marvel Studios, although it's equally likely he could just have meant that he's precluded by his significant responsibilities to write and direct Guardians of the Galaxy 2, which will keep him busy for the next two-plus years.
Either way, it's instructive as to his interests. When a recent photo shoot featuring Gunn and Guardians of the Galaxy star Chris Pratt raised questions from fans by including an issue of Firestorm among dozens of Marvel comic books, Gunn responded in a podcast interview that while he's a "lifelong DC fan," Firestorm wasn't one of his favorite characters.
So, apparently Shazam/Captain Marvel is?
At any rate, it's not in the cards -- and this one offhand Facebook comment will inevitably be picked up by more than just us, and make it one of those "wouldn't that have been cool?" movies people talk about.
Hollywood's pool of currently-fashionable directors has begun to shrink so small that the same handful of names seem to be suggested or rumored for just about all of them. If we're to assume (which is likely a fair but not necessarily accurate assumption) that Gunn's preclusion is contractual and that other Marvel-affiliated directors are similarly limited, that could take a number of the hottest names of the day off the board for all those DC movies coming up over the next five years.