From a CBS News press release:
On the eve of the GOP Convention, Bob Schieffer will anchor FACE THE NATION from St. Paul this Sunday (31) with four top Republicans -- former New York City Mayor Rudy Giuliani, who is also the keynote speaker of the event, Sen. Joseph Lieberman (I-Conn.), Gov. Bobby Jindal (R-La.) and former Hewlett-Packard Chairwoman Carly Fiorina--as well as New York Times columnist David Brooks. [Emphasis added.]
Update: Looks like CBS has realized their mistake and issued a "REVISED" press release with no mention of "four top Republicans." Good thing, too: they were killing Independent Joe.