It's looking like it, says Harry Enten:
I can't take Wisconsin too seriously as a toss-up until I start seeing more candidate visits. The seeming tightening in the polls may prompt it. If it does, then Romney picks up an additional path if we allow for wins also in Colorado, Florida, North Carolina, and Virginia. All he'll need is Wisconsin and either Iowa, or Nevada, or New Hampshire. In this scenario, Romney wouldn't have to take Ohio.
Nate Cohn is skeptical:
Wisconsin could be Obama's best battleground state and it might be the only battleground state where Obama has nearly locked up the votes he needs to win reelection. Although the state remains characteristically tight, post-debate polls show Obama at or above 49 percent—just like 21 of the 23 surveys conducted in the Badger State since the gubernatorial recall election, and a higher percentage than any other battleground state. No, there haven't been many post-debate polls, but the post-DNC surveys showed Obama leading by 7 points–better than any other battleground.
(Chart: Wisconsin poll of polls, with heightened sensitivity, from Pollster.)