For once, Microsoft may be picking the wrong battle, but brother, would I pay to see Steve Ballmer and Marc Benioff in the ring. A long line of opponents lay in the wake of Redmond--Netscape, Sun, the U.S. Department of Justice--but when Ballmer said Thursday that Microsoft would give Benioff's software-as-a-service juggernaut, Salesforce.com, "a run for its money," he may have invited more than he bargained for.