Since Vista, Linux adoption has gone up less then a fifth of a percent. Apple's market share is no better then it was over a decade ago back in 1996 when Jobs came back. I'd say that Vista has totally destroyed Microsoft from those figures. /sarcasm
...and Apple is laughing at your sarcasm, all the way to the bank. The one truth about statistics is that they can be skewed (manipulated) in favor of any given perspective. The truth of the matter is that for the calendar year 2007, Apple ranked number four in new computer sales for the US (per Gartner and IDC--see the January 17, 2008 PCWorld article, "Apple Growth Spurt Continues"). Only HP, Dell, and Acer sold more units in the same period.
Still snickering? Well, let's put that comment into perspective. The figures mean Apple sold more computers than any single of the following companies: Gateway, Toshiba, Lenovo, Panasonic, and Asus. They show Apple saw US sales growth between 28% (Gartner) and 30% (IDC). Also, while it may mean Apple's market share is, in percentages, no better than in '96 that share equates to many millions more units. Apples 5.7% share worked out to approximately 3.6 million units. That's nothing to sneeze at and represents enough numbers to justify software makers investiment of time and manhours to produce programs for the Mac platform. Last, but not least, when we consider the market share was by a single computer maker, in a market that's deemed dominated by Windows, it becomes more evident that Apple is a serious player in the computing world.
Oh... almost forgot. The 28% to 30% growth shown by Apple was greater than either of the three makers at the top of the sales list. HP saw 14.9%, Dell saw 9.3%, and Acer saw 10.7% (from Gartner's US PC sales figures). If the trend continues, Apple could easily see itself climb even higher up the ladder of system sales and market share. If Windows users continue to be disheartened with Vista (which in spite of the Vista cheering section, they are still disheartened), it could well help Apple to win a bigger piece of the pie.
One last point. On the subject of skewed figures, we have to remember that in the middle of '07 Acer acquired Gateway (and as such, eMachines and Packard Bell) which pushed them into the number three sales slot for that year. Had such not been the case, Apple would have owned the third place slot for US sales.