By Adam B. Vary
Updated August 29, 2012 at 12:00 PM EDT
Eric Charbonneau/

The success of any tightly scripted, live event is certainly measured in ratings, ticket sales, buzz, and — with regard to quadrennial political nominating conventions — voting returns. But the real yardstick for any major pop-culture event comes down to one simple element: The surprise celebrity cameo. Recent examples include James Bond and Queen Elizabeth skydiving into the London Olympics Opening Ceremonies; Tupac Shakur’s hologram at Coachella; and when Jon Hamm popped up to say goodbye to Kristen Wiig on SNL.

Hoping to add itself to that storied list, apparently, is the 2012 Republican National Convention. The latest RNC schedule, released on Monday, notes that before presumptive GOP presidential nominee Mitt Romney is introduced by Sen. Marco Rubio, the convention will hear remarks from someone — or something — “To Be Announced.” That tantalizing clue lead today to report via a single unnamed source that actor, filmmaker, and all-around American icon Clint Eastwood is indeed the surprise guest.

Unless it’s football player Tim Tebow. Or former president George H.W. Bush arriving via parachute (the 85-year-old is quite the skydiver). Or, as one aide maybe joked in the story, “a Ronald Reagan hologram.”

These are all choices with serious potential to stir up some major buzz — if the remarks weren’t preceding the biggest speech of Mitt Romney’s political career. That’s the trick of a surprise guest: You want people to be impressed, but you don’t want to overshadow the main event. Would Romney look cooler drafting off of Eastwood or Tebow? Or by comparison would he seem more like a businessman android than some already claim he is?

Who do you think should be the “to be announced” speaker at the RNC tomorrow?

Fun fact! While the 2008 RNC was slight on celeb speakers, the 2004 RNC included actors Ron Silver and Angie Harmon.

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