In an email to supporters, Obama campaign manager David Plouffe writes:

I'm writing to report that we're seeing a surge of support in states we didn't expect to be close contests, including Georgia and North Dakota.

But the latest battleground is a major opportunity:

John McCain's home state of Arizona -- where we go on the air today.

Democrats haven't been able to compete in these states in years -- and each could open a new path to victory on Election Day. Make a donation of $5 or more today to expand our efforts in these new battleground states.

As a bonus, any donation you make today means you could be selected for a trip to join Barack in Chicago on Election Night. We'll fly you and a guest in, put you up in a hotel, and make sure you have some of the best seats for our huge public event with tens of thousands of supporters.

As Kyle noted yesterday, the campaign is indeed spending some resources in AZ, ND and GA.