While Obama has increased leads in the major national polls, it is really the state electoral polls that matter. The following 7 states were won by Bush in 2004 and are in danger of going to Obama in 2008. Most recent Poll results with dates:

Ohio - Obama +1 Sept. 21
Virginia - Obama +3, +6 Sept 21
Florida - McCain +1 Sept. 18
Colorado - Obama +10 Sept. 17
New Mexico - Obama +11 Sept. 19
Nevada - McCain +1 Sept. 21
Norht Carolina Tie Sept. 19

That is a lot of electoral votes that McCain can't afford to lose.