The headline says it all here. As first reported by Latino Review, Josh Brolin will be the voice, and potentially do some motion capture work, for Thanos in the upcoming Guardians of the Galaxy movie. Since Thanos isn’t expected to have a real face-off with the heroes of the Marvel Cinematic Universe for several more films — Ronan the Accuser is supposedly the main physical threat to the Guardians’ well-being — Brolin’s talents will likely be called upon down the road as well.
As IGN points out, Brolin has some prior experience with comic book-related films, from the forgettable (Jonah Hex, though that was so bad it’s actually hard to forget) to the underrated (Men in Black 3, where he played an eerily pitch perfect younger version of Tommy Lee Jones). There’s no question he’s got the voice to give Thanos the proper amount of menace.
If you’re not up on Thanos, we’ll have some recommended reading up in the next few days. Suffice it to say that he’s one of the Marvel Universe’s most evil and devious villains, an Eternal from Titan with a visage not unlike DC’s Darkseid and a long-running desire for Death herself. He’s been vanquished several times even when in possession of some of the most dangerous cosmic artifacts around, but he always seems to pop back up again.
Thanos also has his own annual on the stands right now written by his creator, Jim Starlin, so you can go check that out if you want to see how Brolin might get into character.