There's a fascinating website I learned about recently. It's called fivethirtyeight (which is the total number of electors in the electoral college). The mission of the site is "to accumulate and analyze polling and political data in a way that is informed, accurate and attractive. Most narrowly, to give you the best possible objective assessment of the likely outcome of upcoming elections." The guy who runs the site was recently on CNN and MSNBC. The amount of numbers he crunches is mind-blowing. The below pic reflects what 538 presently believes the outcome will be in each state on November 4:
The blue states go to Obama, the red to McCain (the dark blue and dark red states are more likely to go to that candidate than the light colored versions of each). Under this scenario, the electoral totals would end up being Obama: 298.2 and McCain: 239.8 (270 are needed to win).