Microsoft CEO Steve Ballmer was in surprisingly good form this morning, as he kicked off the company's annual Financial Analysts Meeting. His presentation was one of the best in years. The economy may be cool, but Ballmer is hot. Perhaps his most piercing comments were about Apple, a competitor that has nipped away Windows PC market share and proved to be a formidable opponent in mobile devices markets. Ballmer dismissed Mac shipments of "10 million" units a year as being meaningless. He described Mac market share gains as "a rounding error." Ballmer emphasized: "Apple's share globally cost us nothing." But what he didn't say: Microsoft gained much. In a later presentation, Robbie Bach, president of the Entertainment & Devices division, touted the revenue contribution from Microsoft consumer software, which Macintosh Office is the largest component. Increased Mac sales do benefit Microsoft.