Now it's time to speculate on which character he will play! According to Variety, he will play a villain, but one can never be too sure. We know next to nothing about the plot of this film, other than the fact that it's the sequel to X-Men: First Class.
What I'm personally intrigued by is whether Dinklage's small stature will be incorporated into the role (if not a villain, he would most likely play Puck in that case), OR if they will ignore his Dwarfism completely and just give him whatever antagonist role was already in the script. The latter option would be a moral victory for the producers and there is no doubt in my mind that Dinklage would dominate the role no matter what is required of him.
So, post your speculations in the comment's section below!