This phrase is used to refer to someone you know in a situation that reminds you of them. The name part is substituted by the name of the person you are refering to.
Matt: Guess what?
Charles: What?
Matt: Ron shaved his head.
Charles: What the (name) Britney Spears.
Charles: What?
Matt: Ron shaved his head.
Charles: What the (name) Britney Spears.
by BOSOX2007 March 20, 2010
