The nightclub at Cosmopolitan will be called "Marquee" named after the successful New York City club. Marquee will be operated by the Tao Group. The 63,000-square-feet indoor and outdoor venue will be open 18 hours a day, and is sure to become one of the hottest spots in Vegas once it opens in time for New Year's Eve.
In other Cosmo news, Jay-Z and Coldplay will be performing for Cosmopolitan's grand opening New Year's Eve bash. No matter what you think of them, both Jay-Z and Coldplay are huge acts, and I think it's good for the city to have some high profile artists there for the opening of the new hotel. I don't remember if Aria / CityCenter even had any musical acts to open that huge project last year, so in comparison it looks like Cosmopolitan is doing a good job building some hype and anticipation for their opening.
Source: Robin Leach.