I believe the article says Macs went from 15.5% share of the computer market last month to 60.7% market share.
That is not what the article says. Read my response again. They're talking about year-on-year growth. The important point here is that the percentage they're expressing, if year-on-year, is not indicative of what the sales are as a percentage of total (and they're not talking about Mac sales, but Mac OS sales, btw).
When we talk about year-on-year sales growth, we're talking about the growth in sales expressed as a percentage of the same product's previous year's volume, not as a percentage of the market.
Imagine that in September of 2006 they sold 100 copies of OS X.
15% year on year growth would mean in September of 2007 they sold 115 copies.
Now imagine that in October of 2006 they sold 200 copies of OS X.
60% year on year growth would mean that in October of 2007 they sold 320 copies.
The only market share figure stated in the article is the one noting that OS X, specifically Leopard, represented 53% of total OS only sales at the time. That is an entirely different metric from the aforementioned.
Combined, these metrics are important because they're telling us two things...
The interest in Windows relative to last year declined quickly from September to October. The interest in OS X relative to last year increased quickly from September to October. Taken alone, this metric doesn't tell us why... but that's not the interesting part. The interesting part is when you look at the second metric, and see that yes, indeed, Leopard represents a larger volume of OS sales than Vista in Japan.
One thing to consider, though, as to why Vista sales a year out should be compared to Leopard sales is because Vista had a much longer development cycle, and Microsoft's releases are intended to carry them for years, not 18 months like OS X releases. For such a major release, 6-7 years after XP, to reach maturity in terms of market interest within just a year is particularly terrible. Nothing significant will change about Windows for another several years.
Consequently, it is rather significant that Apple is stealing attention from Microsoft now... because with absolutely nothing of note in the hopper for several years, Microsoft is particularly vulnerable to market share depletion by more agile entities. Perhaps the delays for Leopard were actually a good thing. Any earlier and it may have been somewhat more difficult to swipe market share from Windows. But now, it seems almost like stealing candy from a baby.
Remember, because of Microsoft's tremendous size, a drop from 75% year over year growth to 28% year over year growth is a staggering slowdown in volume being pushed out the door.
Apple combining forces very heavily with Google for content delivery is a double-blow... separately they don't seem capable of doing so much damage, but together they pose a significant threat to Microsoft because the future of the OS is predicated heavily upon the user experience and content accessibility... something Microsoft is very lousy at facilitating. People are becoming more and more interested in what their OS can do for them in terms of both content creation, content transmission and content access over the internet.
Microsoft's in a very precarious position right now, very heavily exposed due to multiple failures in content creation/delivery, OS stability and security, and the overall user experience.
This is not simply about selected numbers making Mac OS appear better. This is about a small, very agile entity's window of opportunity (no pun intended) to grab market share and build brand equity while the sleeping giant of Redmond takes another several years just to figure out its next move, much less act on it.
i love my mac, my ipod touch and leopard. Watchout you PC lovers.. mac is in town!