WI never was, is not, and never will be a possibility.
Tell that to President Obama, who is headed there twice in the last five days of the campaign.
Either the internals are telling him that he needs to get to WI to shore up some "soft" support or the margin is too close for comfort. In either scenario, WI is in play.
As I pointed out to you in another thread, Wisconsin is a twofer state, with a Presidential race that looks solidly Obama, but not 100% certain, combined with a very close Senate race. If there was no Senate race, or it was a lock for either Baldwin or Thompson, I doubt Obama would be spending time there.
We can agree to disagree on that one. Conventional wisdom would suggest otherwise. There's only a limited amount of political capital to be expended at this time in the campaign. I doubt the Obama campaign is that overconfident of a victory where they are looking at downstream races, even if they are two-fers.
I'd submit that the fact that Wisconsin isn't 100% certain is a motivating factor in terms of what twofers the campaign bothers to pay attention to with its at this point very limited remaining time, but doesn't necessarily mean the state's entirely up for grabs on the Presidential level; you're entirely right in that Obama isn't going to, for instance, North Dakota or Montana (then again, those are states where he may not help the Democratic Senate candidates).