Ohio Wesleyan's political science professor Joan MclLean offers an interesting opinion on the potential dream ticket:

This year, a ticket uniting Clinton and Obama would have to overcome one last taboo: “It would not have one of the traditional characteristics of a presidential ticket,” said Joan McLean, a politics and government professor at Ohio Wesleyan University. That is, neither is a white male. Like a lot of people, McLean wonders if Clinton or Obama is willing to take that risk.

The most storied of these whirlwind courtships came in 1960, when primary foes John F. Kennedy and Lyndon B. Johnson got together for what proved to be a winning ticket.

Johnson was the legendary Senate majority leader; Kennedy was the 43-year-old upstart. Kennedy’s brother Bobby, the campaign manager, loathed Johnson. Johnson was hardly fond of either Kennedy, particularly since the young senator crushed the wily Texan in that year’s primaries.