If he wins Florida but loses either Ohio or Virginia, he will fall short, even winning both Colorado and New Hampshire.
Pennsylvania and Iowa seem out of his grasp. I think it comes down to Ohio, Virginia, Colorado and New Hampshire.
Out of 2.7 million voters in Colorado, 1.7 million have already voted. Republican early voters outnumber Democrats by 25,000 so I won't be surprised if Colorado goes to Romney. Things that could make it go the other way: Independents (more than 400,000 have already voted) and Amendment 64 (to decriminalize personal adult possession of small amounts of marijuana).
I still believe President Obama will win either comfortably or in a squeaker. Nate Silver now predicts Obama will get 307 electoral votes.
But you need to vote. Every vote counts towards winning a state. Don't rely on polls, or the belief you are in a "safe" state. The race is too close.
Update: Public Policy's final election poll out today increases Obama's probable electoral college votes and shows Obama with a 6 point lead in Colorado. The only two states not leaning one way or the other are North Carolina and Florida.