With the release of Guardians of the Galaxy, Marvel Studios branched off into another part of their universe, the cosmic side. After 10 movies, Marvel's plan for Thanos and the Infinity Gauntlet is now becoming clearer, as the comic book movie studio introduced three of the six Infinity Stones that make up the most powerful weapon in the Marvel Cinematic Universe and gives its owner omnipotence, omniscience, and God-like power. Let's run down what was introduced and what we might see in future installments, shall we...
Introduced in Thor and expanded upon in Captain America: The First Avenger, Marvel Studios introduced the Space Gem in the form of the glowing-blue Tesseract. Loki wielded its power in a special scepter that the Chitaruri alien race gave to him at the beginning of The Avengers. While he used to control Hawkeye and other members of S.H.I.E.L.D., producer Kevin Feige confirmed that this Infinity Gem was the Space Gem and not the Mind Gem like many were led to believe. This was the object at the center of the Marvel Cinematic Universe for three films, as it now rest safe and sound in Odin's Vault on Asgard.
In the sequel Thor: The Dark World, another Infinity Gem was introduced to the Marvel Cinematic Universe, the Reality Gem, in the form of the Aether. While it's not explicitly stated in Thor sequel film, the Aether is believed to be the Reality Gem because it gives its possessors the ability to freely move from world to world, IE Natalie Portman's Dr. Jane Foster transporting from Earth to Asgard. At the end of Thor: The Dark World, Volstagg and Sif give The Collector the Aether because it's not safe to keep two Infinity Stones so close together with the Tesseract on Asgard.
Now we come to Guardians of the Galaxy and the Purple Power Infinity Gem. This was the object of desire throughout the entire film. While it was ultimately a MacGuffin, the Orb will rest safely with the Nova Corps, until Thanos comes for it. Guardians of the Galaxy also expanded the Marvel Cinematic Universe, much like Nick Fury did at the end of the original Iron Man. It hints at more elements in the film franchise, such as the Nova Corps, which can be seen as a space version of S.H.I.E.L.D., much like S.W.O.R.D. (Sentient World Observation and Response Department) in the comic books.
Marvel Studios has yet to introduce the Soul, Mind, and Time Gems, which will all likely be introduced before The Avengers 3 when it's believed Thanos will finally be the big villain. If we look at the upcoming Marvel slate, we can probably guess when they would come into play.
In 2016, Marvel is believed to introduce general audiences to Doctor Strange, the comic book movie studio's Sorcerer Supreme. Doctor Strange will play into the mystical and magical side of the Marvel Cinematic Universe, so it's likely the Soul Gem will be introduced with this character and movie. The Soul Gem gives its owner the ability to control a person's soul and in the comic books, Doctor Strange was one of its owners, along with Loki, Nebula, and Adam Warlock. You can rest assured that the Soul Gem will turn up in Doctor Strange.
Also in 2016, Marvel will release Captain America 3, which would most likely introduce the Time Gem. Considering that Captain America is the only character in the Marvel Cinematic Universe that isn't in his own time, I could see him using the Time Gem to go back in time to the 1940s. A majority of these movies fall into the science fiction genre and we have yet to see time travel in any of them, so it seems like a good opportunity to introduce that element. Maybe we could see it in Guardians of the Galaxy 2 with Star-Lord wanting to go back to his time period in the 80s. Aside from Captain America, Star-Lord is a character that longs for another era.
Which brings us to the Mind Gem. While it's unclear which movie franchise would feature this Infinity Gem, Marvel could introduce it in a new franchise like they did with the Power Gem and Guardians of the Galaxy. Marvel could introduce Ms. Marvel to their cinematic universe to set up the Mind Gem and introduce her as a member of The Avengers. This would also give Marvel another opportunity to introduce another strong female character, who would most likely have her own movie, while we're still waiting for one for Black Widow.
Needless to say, we have plenty of time to see the remaining Infinity Gems on the big screen, while Thanos has yet to truly reveal himself to general audiences and Earth's Mightiest Heroes. While Marvel has release dates for untitled movies until 2019, the remaining question is what will the comic book movie studio do in the next decade.