My bet is that he will. He's usually ahead of the trends, not following them, so I'm surprised he's not already here.
The problem is that it's in still in beta stage here- one of the problems to overcome is that's it's hard to find things you are interested in. He can let his current followers know he's here and they can register (a huge boost to steemit). Otherwise it's like starting all over again - I know people sometimes look at the tags, and he can generate a geraldcelente one - I would follow him if I found that - but it takes word of mouth to get that out...
But I LOVE the fact that you were the one to let him know about Steemit. Feels like watching history happen ☺