Quite what "everything else" might mean in this situation is interesting to speculate about; in terms of its comic book mythology, there are literally half a century's worth of other characters and concepts to use, even outside of the properties licensed to Sony or 20th Century Fox — but in terms of the long-standing "families" of characters, there are obvious gaps needing to be filled.

While Avengers and related properties mean that straightforward superheroics are well accounted for in terms of the Marvel movies, there are other schools of Marvel superhero thought that have yet to show up on the big screen, and may never make it. Both "street level" heroes like Luke Cage, Jessica Jones and Daredevil and supernatural "horror" characters like Ghost Rider are already spoken for on television. The Inhumans — still, in theory, at least, are scheduled for their own movies circa 2020 — and have also been well-established via Marvel's Agents of SHIELD since that show's second season.

The space setting of Guardians of the Galaxy opens the doors for Marvel's many cosmic characters — indeed, that movie's use of intergalactic police force the Nova Corps makes the prospect of a stand-alone Nova movie, based on the 1976 comic book, low-hanging fruit. Other, similar projects, such as Warlock, Quasar or even intergalactic disaster story Annihilation could follow suit.

Thor brings in a whole range of mythological leads that Marvel could spin out into their own movies, as well; just as Hercules, Ares and other Asgardians such as the Warriors Three or Balder the Brave have headlined their own comics, so could they their own movies. Iron Man could lead to more technology-based projects — Machine Man, created by Jack Kirby, for example — while SHIELD alone offers up the potential for a small army of new heroes.

To date, Marvel has mostly stayed close to the comic book roots of the Avengers when choosing big-screen projects (With the exception of the Guardians, every Marvel movie hero has been an Avenger at one time or another), but there is also the potential to look much farther afield for future material: Devil Dinosaur, which is pretty much what it sounds like, say; Weirdworld, in which the bizarre setting is as much a character as any inhabitant, or even a genuinely off-genre entry like Models, Inc. in which a number of models have to team up to solve a crime to prove a friend's innocence.

When Feige says that Marvel is left with "everything else," it could sound like a hollow boast — the Marvel back catalog is filled with a lot of dross and chaff, as one might imagine for a company that's been producing new content for more than 50 years — but there remains all manner of potential to be uncovered and transformed into the next big movie thing. "Everything else," it turns out, is enough to keep Marvel busy for at least another half-century, if not longer.