(Warning, potential SPOILERS for future movies in the Marvel Cinematic Universe - and the current Marvel Comic-Book one - lie below. Tread softly, and all that...)
Now, the Marvel Cinematic Universe may well only now be finishing up with its Phase 2 - its second set of thematically-linked movies, beginning with Iron Man 3, and continuing through till the recently-released Ant-Man - and the already-announced Phase 3 line-up may not yet have arrived, but that doesn't mean it's too early to start thinking about the still-distant Phase 4.
After all, with the current slate of Marvel Studios movies (from next year's Captain America: Civil War through to 2019's Inhumans) already fairly locked in, we can already get a pretty solid idea of just what the Marvel Cinematic Universe will look like as Phase 4 begins. Specifically:
Marvel is About to Need a Whole New Focus
After all, Thanos - the big bad looming over every Marvel movie since The Avengers is likely to have been defeated by the close of 2019's Avengers: Infinity War Pt 2. That, though, is likely to come at the cost of several of the original Avengers's lives - many of whom's actor counterparts' contractual links to Marvel will coincidentally end at the same sort of time.
In the absence of Thanos, then, what direction is the Marvel Universe most likely to head in, come 2019? Well, if the current shake-up of Marvel Comics is any guide:
We Could Be About to See (the Road to) Secret Wars
Specifically, it's entirely possible that Marvel Studios will take the mild rebooting necessitated by the likely contractual expiries at the end of Phase 3 and use it as a lead-in to the major crossover event currently rocking the Marvel Comic-Book world - Secret Wars.
The by-product of decades of temporal disturbances, Secret Wars was prompted by the Marvel Universe as we know it (as well as all alternate ones) essentially ceasing to exist, and instead being replaced by a 'Battleworld', a planet made up of miniature 'mash-up'-like versions of Marvel universes. At its end, we're set to end up with a Marvel Universe similar - yet in some key ways different - to the one that's existed for the past 76 years or so.
Or, in other words:
Adapting Secret Wars Would Allow Marvel Studios to Painlessly 'Reboot'
After all, by 2019, Marvel may well be scrambling to replace fan favorites like Robert Downey Jr, Chris Evans and Chris Hemsworth, and while that's likely to go pretty well - the Marvel Studios gang have given us little reason to doubt them up till now - it's also entirely possible that it'll also see a reduction in box-office grosses.
If so, then gradually building up to another major crossover event along the lines of Avengers: Infinity War would obviously make a solid amount of commercial sense - as would creating an opportunity to change things up. With a (presumably loose) adaptation of Secret Wars, Marvel would have the opportunity to re-introduce beloved actors or characters who had previously departed the MCU back into the cinematic fold. In fact, the possibilities are pretty much endless.
Heroes Could Return Unscathed
Captain America, after all, has long been rumored to end up dead in the near future of the MCU, and to be replaced by either Bucky of the Falcon in the role. If a new Captain America isn't selling tickets by the 2020's, though? Don't worry, Chris Evans can always (have a sack of money thrown at him, and) be brought back in from an alternate universe.
Heroes Could Return Completely Changed
The absence of Iron Man causing financial woes? Bring in a new, cheaper version of Tony Stark from a reality where he doesn't look like Robert Downey Jr, and throw him into Iron Man 4. Chris Hemsworth looking a little too old to play Thor? Never fear, the comics have already introduced a bad-ass female version of the hero who actually out-sells her male counterpart. A new actor asking for two much money? Don't worry, there's another version of them out there somewhere, and the big, end-of-phase blow-out can introduce them.
And, of course:
Profitable Heroes Could Be Doubled Up
The most intriguing possibility? A cinematic Secret Wars - which would presumably not appear until the mid 2020's - could even allow multiple versions of the same hero to appear in the MCU, much as they're about to in the comics.
Or, in other words, we could see Miles Morales and Peter Parker swinging around - and who doesn't want to see that?
Now, this might all be a long-shot, and it wouldn't be likely to actually affect the movies we'll see until around 2024 - meaning Phase 5 - but while it's currently mere speculation, it could eventually provide an intriguing solution to a series of problems that're very much on the horizon, in about the most awesome, comic-book-faithful way possible.
What do you reckon, though?