Josh Brolin recently did some press for his latest movie, Inherent Vice, where he mentioned what he liked about the Thanos role for Marvel Studios.
Marvel Studios recently released the titles of the next two Avengers movies with The Avengers: Infinity War Part 1 and 2, which will feature Thanos as the big villain. From Brolin's comments it's obvious The Avengers will be taking on Thanos. We can also speculate the two movies will be using new characters for the film (especially with Thanos in two films).
Brolin continues talking how he nabbed the role and why Thanos is an exciting character.
“Thanos came along because of my good friend Louis D’Esposito,” Brolin continues. “…He and I used to train together. We did ‘Hollow Man’ together. He called me up and started talking about this thing. It was nice because I could intimately talk to him 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.”
Previous to Brolin being officially announced as Thanos, it was also stated Brolin and the Mad Titan will be appearing in The Avengers: Age of Ultron.