As you know, there have been rumors about Vin Diesel playing Groot in Guardians of the Galaxy, rumors that the actor basically started himself! I was actually really hoping he would play Thanos, but it looks like he is actually in the running to take on the role of the giant tree creature. He recently did an interview with The L.A. Times in which he talked about the reason he is looking at taking it saying,
"I’m an actor, [N]ot everything has to be the most obvious choice. And sometimes, the best thing you can do — as far as Steven Spielberg and his advice — is to defy expectations. So if everybody thinks you’re going to go for this one thing and you flip it entirely and go for the strangest Marvel character, it’s interesting. And when something is interesting, it’s inspiring."
Diesel goes on to talk about how Marvel feels about him teasing the character he is looking to play on his social media outlets.
"The last thing they are is mad, I’m pretty open, but I have been secretive about this. I went to Comic-Con and I got blasted while I was on the Hall H panel for 'Riddick.' Someone asked a Marvel question. I couldn’t say anything because of that secrecy."
The movie also stars Chris Pratt, Zoe Saldana, Dave Bautista, Lee Pace, Michael Rooker, Karen Gillan, Djimon Hounsou, Benicio del Toro, John C. Reilly, and Glenn Close. It's currently shooting in London and will be released on August 1st, 2014.