The campaign today sent its second email on the topic to supporters, and it opens with a sign that people didn't take the first message too seriously.
"People keep asking me if we're really going to announce Barack's VP directly to our supporters," campaign manager David Plouffe writes. "The answer is yes. Let me be very clear. You are the ones who built this campaign, and Barack wants you to be the first to know who will join him in leading our movement for change."