Senator Mel Martinez, Florida
Governor Charlie Crist, Florida
Dr. Henry Kissinger
Governor Huntsman, Utah
Governor and 9/11 Commission Chairman Tom Kean
John Chambers, CEO of Cisco
Carly Fiorina, Former CEO of Hewlett-Packard
James Huffines, Banking Executive
David Pottruck, Chairman of Red Eagle Ventures
Frederick W. Smith, CEO of FedEx
Dax Swatek, President of Swatek and Associates
John Thain, CEO of Merrill Lynch

Just a few of a lot of key endorsements.

Complete lists here.
http://www.johnmccain.com/supporters/