The opening party of the Cosmopolitan hotel in Las Vegas, going down on New Year’s Eve, will feature performances from Jay-Z and his pal Chris Martin’s band Coldplay, each copping up to a cool million bucks to play. Also on hand will be Jay’s and Chris’s respective significant others, Beyoncé and Gwyneth Paltrow, although they will not be performing (officially, that is). But, yeah: Best double date ever! [Page Six/NYP]