Today CNN moved Nevada from "Tossup" to "Leans Obama," making it 291 for Obama vs. 163 for McCain, with only 270 required to win.
Apparently most of the polling shows a tightening of the nationwide margin, but a WIDENING of most margins on a state-by-state basis. For example, some of the states that had leaned toward Obama are now considered safe. Making that kind of change to the map does not affect the electoral count that CNN reports, but it does add confidence to the count.