When I look at this, it sends shivers up my spine.”

– Apple COO Tim Cook demonstrates a new MacBook running Windows

If there was any comic relief during Tuesday’s Apple event, it was provided by Microsoft (MSFT), which played Curly to CEO Steve Jobs’s Moe and COO Tim Cook’s Larry. Discussing the dramatic increase in the Mac’s market share in the past year, Cook said it was driven partially by “something we didn’t do: Vista.”

“I think it’s fair to say that Vista hasn’t lived up to everything that Microsoft hoped it would,” Cook said. “And consequently, it’s opened doors for a lot of people to consider switching to the Mac. And Apple has been the beneficiary of this.”

Recognize misfortune for what it is: an opportunity to lift yourself to a higher level, eh, Tim?

Anyway, according to Cook, 50 percent of all new Macs sold are purchased by switchers. Moreover, the Mac has outgrown the market for 14 of the last 15 quarters. That’s nearly four years. “The Macintosh represents 17.6 percent of all unit sales in U.S. retail,” said Cook. “That means one out of every three dollars spent on computers in U.S. retail is spent on the Mac.”

A remarkable point. And one seemingly borne out by the latest PC vendor shipment numbers from Gartner (IT) (click on chart below). Apple (AAPL) showed nearly 30 percent year-over-year growth in the third quarter, its market share rising to 9.5 percent from 7.7 percent.