President Bush and President .... (fill in the blanks)

Today, President Bush met with the man who is going to succeed him at the White House, as we can see in this photo :

But he does not know who this man is yet...

Only forty days before a general election, this is the first time an incumbing president has had talks with both candidates at the White House.
Really, this election does not look like any other !
And I've got the impression that there may well be other twists of events very soon...