Famous people tend to have a lot of time and money and the ability to entertain themselves in ways that we peasants cannot.
Therefore, I would be willing to bet that "no, there is no one famous here."
I don't know.
There are a number of celebs that have acknowledged the fact that they play or played WoW.
I wouldn't be surprised if some famous person is captaining a ship in game.
I would be surprised if any of them announced their presence to the rest of the player base (at least beyond saying that they play that is). Lets face it, playing online games offer a small chance at being just another, ordinary person. If a celeb's "@name" was ever discovered, they'd have to create a whole new account.