Josh Brolin, in an interview about his next movie Inherent Vice, talked a bit about MCU and his portrayal of Thanos. First, he revealed why he chose to accept the role of the Mad Titan, by saying that the character is, basically, one against all. Then the actor explained how the chance found him, explaining that this villain is interesting not just as an iconic comic book character: "It was nice because I could intimately talk ["¦] about it. What I liked. What I didn't like about the whole idea of it"¦ It was really exciting because of the possibilities that it could be come. Not as an idea or as a blockbuster, but just as something different. It's a character mentality."
When will Thanos appear again in the MCU?
Of course, Thanos will be the central character of the Avengers: Infinity War (both part 1 and 2). However, he might as well appear in other movies until then.
In an interview with Nuke the Fridge, Josh Brolin mentioned two dates: 2016 and 2017. Given the release date of Avengers: Infinity War - Part I (2018), it is safe to assume that Josh Brolin will enter once again the huge boots of Thanos in 2017 (Infinity War part 1 and 2 will be shot back to back).
However, the 2016 date makes us think about something else too"¦
Could Thanos appear in Guardians of the Galaxy 2?
This is a strong possibility, given the fact that Thanos is a threat to the entire galaxy - we may see him taking on the Guardians before arriving on Earth. If this happens, it is safe to assume that the Mad Titan will defeat Star Lord and Co before facing the Avengers.
Could this mean that at least one of the Guardians will appear in the Avengers movies? This could work out on many levels, given the threat Thanos poses.
Anything else?
Well, until now only 4 Infinity Stones have been revealed: the Tesseract, the Mind Stone, the Aether and the Orb. This means that there are still 2 gems to be revealed - so besides Guardians of the Galaxy 2, Thanos might also pop-up in Captain Marvel, Inhumans or even Doctor Strange (as Infinity Wars are closing in, it makes sense seeing him popping all over the place).