In the coming weeks, Obama will pick up a few more states, and he will lose a few, too (nothing is more annoying these days than the Chicken Little proclamations by some Obama supporters that the sky will fall if he loses, say, Indiana: that has zero basis in reality; the sun will still come up the following day, and he’ll be even closer to the nomination in delegate math). But the overriding dynamic is already bigger than can be affected by the momentum coming out of a particular state, and the movement continues toward Obama.
I share Al's irritation with the "chicken littles." It's about delegate math, and Pennsylvania, while not a win, actually put Obama closer to the nomination by taking the largest remaining pile of delegates and votes off of the table without a huge blowout for Clinton.
Indiana, however it comes out, will likely be the same. Then the next biggest state. Then the next. It's a long, drawn out process, but that's how it works and by not conceding a bunch of states, Obama set himself up to win it. It looks like that plan is working.