Maybe a definition of bellweather would help. I'm not the one to give it, as I see two conflicting ideas of what one may or may not be.
My definition for bellweather is having the sum of the enviroment of the election boiled into one state, so that the direction of that one state is the tipping point for both sides.
Basically, I beieve if Kerry wins WI, he will also win PA, IA, and flip NH. That brings Bush's EV total down to 274, and if Kerry wins WI, chances are he will also flips one of the following: NV, AR, or CO.
But, if Bush flips WI, then he probably maintains everything from 2000 except NH and can offord a surprse loss of either NV, AR, or CO...thus I don't see how Kerry wins the election if he loses WI.
I think WI is a must win for both Bush and Kerry.