Britney's announcement to be "biggest announcement in Vegas history" according to private invitation

Employees of Planet Hollywood, Ceasars Entertainment have received a special e-mail to invite them to "come play a part in the biggest announcement in Las Vegas Entertainment History”.

The invitation says guests will be take do an undisclosed location from Planet Hollywood for the event which is also said to "generate global media attention".

The invitation is private, but more on it will be unveiled on Sept 17th