JL, I also read that McCain "may" drop Pennysylvania as well, although I can't confirm. According to all the pundits, he supposedly has no choice but to go negative.
If he quits Pennsylvania, the election is OVER.
Most of Obama's adds here have been focused on registering new voters, and a record number of registrations are in the books. PA's deadline for voter registration is tomorrow. Barring something unusual, PA should be a comfortable win for Obama.