Sen. John McCain has decided on a running mate, though the No. 2 remains a mystery, for now.

But the Associated Press is reporting that one candidate on the short list, Minnesota Gov. Tim Pawlenty, abruptly canceled several public appearances.

That's an interesting development, but who knows? McCain, like Sen. Barack Obama a week ago, is keeping his choice a closely guarded secret.

McCain will introduce his running mate Friday in Dayton, Ohio.

-- John Guerriero