I wondered about this from the first episode, when they essentially built Ken Jennings up as a celebrity player. Why not have celebrity mob members? Seems like a possibility for NBC cross-promotion too. (We have six cast members from Heroes!)
To hear Ken's account on his blog, they felt they had to treat him -- and all mob members -- just like any other contestant, but surely they're handling Wink and Bob like celebrities. As long as everybody plays the game fair and square, we already know that they can put whomever they want in the Great Big Set, so what's the big deal if some of them are "stars" and get a nicer dressing room, expenses paid, stuff like that?