This whole thing in WI has been going on practically on my doorstep (the Capital is just a few blocks from campus) and shows no sign of letting up, although most area schools have finally reopened after widespread teacher walkouts. Now, I generally feel the way NGTM-1R does about unions, namely that they once had a genuine purpose, but have now mostly outlived their use. The teachers' union in particular has been a PITA; IIRC the last time former Gov. Doyle tried to get concessions out of them, he bacically got a "Go to Hell" in return. My only problem is that this time around, Gov. Walker never even tried to bargain with them first, he just introduced a bill that removed a lot of their bargaining power in the name of balancing the budget. The unions have since agreed to the other concessions, namely paying more towards their pensions and health care, on the condition that their collective bargaining is not touched. In other words, they've agreed to the things that will actually save the state money and help balance the budget, so I fail to see how removing their bargaining rights helps with the short term budget problems that this bill is all about.
As far as the Dem. Senators leaving the state, from what I've heard, no one really knows what can be done. As long as they're outside of the state, there's really nothing that can be done to force them to report in for a vote. Even if they return to WI, there are conflicting laws about what can be done. One law states that, if they are in the state, they must report in to vote, but another law states that senators can't be arrested while Congress is in session except for a major offense. AFAIK, they technically would have to go in to vote, but there's nothing the state can really do to force them to report in if they decide not to. Regardless, they have so far remained out of state to avoid that issue.