There's no rule about when a running mate is chosen. It used to be considered bad form to choose one before the vote was taken and the candidate was made official. As soon as the DNC announced he had enough votes to win, Obama became the one who decided what the rules would be. The King engineers his own coronation.

Michelle Obama has appeared in some very attractive outfits, but the dress she wore for the DNC speech was not one of them. Of course the lemmings are buying whatever they see her wear. Lemmings are like that. Comparing her to Princess Jackie is absurd. "Great designer in Chicago" just doesn't have the ring that "great designers in Paris" does.