This is historical election and it can go either way.
1) It can be landslide victory for Barack Obama if the Floridian (Jews & Hispanics) voted for him in Florida and if he is able to win Pennsylvania and Virginia
2) A marginal victory for Obama if he loses Florida, Indiana but still manage to get Pennsylvania, Virginia.
3) Miscalculation on this part by not picking Clinton. He may win popular vote and lose electoral votes and ultimately lose this election.
Florida, Pennsylvania, Missouri, Ohio and Indiana are the tossup states. According to CNN, all Obama as to do is hold on to Blue states and win Pennsylvania to get the 270 electoral votes.
My latest prediction (I could be wrong):
Missouri, Ohio and Florida will mostly likely go for McCain. Barack Obama has good chance of wining this election If he can win blues states, plus Pennsylvania and Indiana.
Barack Obama will get 284 electroal votes and McCain will get 254 electoral votes.