CNN has a handy little delegate counter that you can use to predict the delegate count based on the election results in all states left and the remaining 'undecided' superdelegates.
http://www.cnn.com/2008/POLITICS/02/29/delegate.counter/So lets have fun with numbers:
Lets say Clinton manages to win every state left 70% to 30%, something even the most rabid Clinton supporter would only dream of, with that scenario (and you can duplicate this yourself) Obama could still win the nomination if 3/4 of the supers swing toward him.
Similarly, if every remaining state voted 60 to 40% for Obama, but all the remaining 311 supersswinged to Clinton, she wins. Remember this doesnt account for the fact that there are in fact ~800 supers and they can switch at anytime their support. So effectively, if all 800-or-so went for Clinton, even victories of 70% to 30% by Obama in all states remaining (something the biggest Obama fan would say is impossible) would not stop Clinton from winning, not even close!
Now, if the superdelegates should *choose* not to decide the race, by splitting 50-50, Obama is pretty much guaranteed to win. Even if NC breaks 50-50, all other states would need to swing at least 60-40 in favor of Clinton in order to keep Obama from winning outright (and 85-15 for her to win outright).
Keep in mind that many possible scenerios result in no majority and a brokered convention. Barring some massive swing of voter opinion that would be completly unprecidented, the superdelagetes have the say in this election. They could let the people decide, or decide themselves, or intentionally broker the convention.
With that in mind.... RE-ELECT GORE '08!! :P