What do you think? Could Thrall lift Mjölnir? My vote is yes.
He fights giant monsters and he's a heroic figure that controls lightning. He's already good with a hammer. His carbon nanotube-reinforced depleted-uranium plot armor makes him at least semi-divine, so he's got the whole Green Jesus thing going for him.
Alternatively though, you could argue that the Hulk couldn't lift Mjölnir and he's green.