https://ww w.youtube. com/watch?v=WH2ri8RhSnw - link broken just in case people don't want to know the new cast members.
Announced at the comic-con panel today, he'll be playing a big character in season 5. I wouldn't consider knowing this character a spoiler of any kind really, but just in case, I'll put it in spoiler tags below:
Really chuffed by this news. Seeing any Trek actor break the curse of never getting a big role again, is great.