The most interesting thing I heard in Obama's speech--besides the fact that he called Indiana for Hillary before the networks did--was his appeal for party unity. A few weeks ago, when Obama spent the bulk of his Pennsylvania concession speech talking about McCain, it seemed forced, like he was trying to deny the fact that Hillary's win was a setback for him. But tonight, he talked about Hillary a lot and he made an explicit appeal to her supporters to back him should he win the nomination. When Obama looked to November after Pennsylvania, it felt fake, like he was a candidate pretending to be unfazed. When he looked to November tonight, it felt completely natural, like he really was the de facto nominee.