Kevin Feige confirms that things will be radically different after the untitled Avengers 4 movie. We can surmise that there will be more crossovers between unlikely heroes and the huge expansion of Marvel's cosmic universe, considering how well Guardians of the Galaxy and Infinity War are doing. Guardians director, James Gunn, is confirmed to helm the development of the cosmic universe. And while we wait, let's talk about the possible movies Marvel Studios will use to milk our money.
Secret Invasion is a storyline where several Marvel characters have been secretly replaced by shapeshifting aliens known as the Skrulls (Like that really old movie, Body Snatchers). The upcoming Captain Marvel movie, starring Brie Larson, will take place in the '90s with two alien races warring on Earth: The Kree and the Skrulls. Given the timeline, the Captain Marvel movie appears to be the perfect setup of a future Secret Invasion storyline where Captain Marvel and a few heroes take on the world.
Richard Rider is the cosmic hero known as Nova, a member of the Nova Corps that was introduced in Guardians of the Galaxy. He can fly, shoot lasers out of his hands, and has a pretty cool armor. His appearance in the MCU can lead to multiple cosmic stories such as Annihilation and The Thanos Imperative.
The cosmic villain Annihilus leads an armada into the universe to destroy planets. Nova teams up with the Guardians of the Galaxy and other unlikely characters to put a stop to this, because destroying planets isn't cool. The story involves Silver Surfer, Galactus, and Ronan the Accuser. Given that Disney acquired Fox, it's not too far fetch to hope the former two makes it to the MCU in a few years.
The Thanos Imperative
Creatures appear from a tear in the universe called The Fault. Their leader is an alternative version of Captain Marvel - lazily named Lord Mar-Vell. Nova and the Guardians, along with Thanos team up to deal with this threat. Considering how we don't exactly know the fate of Thanos in Avengers 4, re-using him would most likely undermine his character. So if the MCU decides to adapt this story, we'll have to see who will act as a stand-in for Thanos.
To put it simply: Some cosmic being named The Beyonder kidnaps several heroes and villains from Earth and makes them punch each other. Now that's popcorn fun, pure and simple.
There are a ton more Marvel storylines out there that can be adapted to the big screen. Let us know what you're hoping to see in the future!