No Wisconsin has always been this way. I understand that you now need an ID to register the first time, but they will accept alternate forms of ID, and let you vote provisionally.
I remember last election, a rally for Kerry was held in Madison the weekend before the election, and after the rally, the Kerry campaign literally paraded a group of unregistered voters down to the town hall and had them register, and vote absentee on the spot. (We don't have early voting in Wisconsin, but you can vote absentee at you County Clerks office.)
There IS a reason that Wisconsin went Democrat the past two elections by only a few thousand votes.