Don't underestimate Michael Jackson and the power of Vegas. He will put 10,000 a night in with NO PROBLEM.He could sell out stadiums all around the world. This is merely a speed bump.
he won't make it in Vegas - where an act has to sell out night after night after night at $200+ per seat, like Celine does. sure, for the first two months he will do it. but there will also be alot of people who would never stay at or set foot in the hotel he was performing at, they would boycott it (I would).
he could tour however, from city to city, and likely fill arenas in cities across the globe. I suspect that is what he will do.