UPDATE
With 3 weeks left, Obama's probability of winning has dropped to 66.0%, down from 78.4% last week. The current electoral forecast is 289 Obama, 249 Romney.
Also, of the 9 swing states that pundits say will decide the election, 5 shifted their outlooks rightward over the past week:
Colorado: previously was lean Obama, now is a tossup
Florida: previously was lean Obama, now is lean Romney
New Hampshire: previously was likely Obama, now is lean Obama
North Carolina: previously was tossup, now is lean Romney
Virginia: previously was lean Obama, now is a tossup
The 4 swing states that haven't budged:
Iowa,
Nevada, and
Ohio still lean Obama, while
Wisconsin is likely Obama.
http://fivethirtyeight.blogs.nytimes.com/