Wait For It Meaning

(idiomatic, colloquial) Used to draw attention to and build suspense, often ironically, for a remark to come.

Example: 2011 February 10, Carissa Dimargo, “'Crimes of Passion' Glorified for Valentine's Day‎”, NBC Washington:
  The National Museum of Crime and Punishment invites couples to "delight their dark side" this Valentine's Day weekend with -- wait for it -- stories of violence against romantic partners?