Well, it helps if we stick to one measurement or another and not bounce back and forth. When the article talks about Linux over taking Apple at 3.2%, that is in US market share where Apple is reported to be at 3.2% also.
Apple's figures for their US market share are at about 5% which is what Jobs refers to.
It went down to 5% before Steve Jobs came back.
According to what numbers? World wide or US? Apple's unit sales increased every year until 2001 as I recall, and then stayed stagnant until 2003 when things started picking up again (for the computer industry as a whole).
Apple is one of only a few companies in the tech sector that was hurt the least during the tech recession.
And the astonishing thing for a Steve Jobs loving Mac fan: It went _further_ down in the time since Steve's been back.
Between 1997 and 2000 there was a greater increase in the total numbers of PCs sold than Apple increased their total sales over the same period. The total unit sales of both Apple and the PC market in general have been stagnant (at least in the US) since 2001. Apple sells more units today than at any other point in it's history... unfortunately more PCs are being sold today than at any point in history also.
I would point out that things could have been worse. Gateway, which was trading at $85US in 2000 is today at about $4.5US (up from a low of around $2US a year ago). They pulled out of the Asia market in 2001 (which includes Japan and Australia) and then out of the European market in 2002. Apple dropped from about $65US in 2000 to a low of about $13US and was as high as $24US this week. And Apple hasn't pulled out of any markets during the last 4 years.
And as has been pointed out, Linux isn't one operating system any more than Unix (System V) or BSD are. Like I said before, four or five operating systems would be nice... Linux is made up of more than that. And like with Unix, not all Linux distros are the same, and not all software can run on all distros (specially if it is commercially made software without source code). The Mac OS is still more widely used than all Linux and Unix versions combined (last estimates I read had total Apple systems at around 10% of world wide systems in use), mainly because of a longer life span than other hardware (PC are made to be replaced every 18 to 24 months, most Mac users keep their system from 3 to 5 years).
I for one find market share data to be hard to justify. First, it is totally based on what system are being sold, not used. Second, it completely disregards people who buy a PC and then remove what ever came on it (replacing it with something else). I, for one, haven't been counted as part of Apple's market share since fourth quarter 2000... and I currently own 11 Apple computers.
I would think more research would put your fears to rest (or at least keep them at bay). Apple is a healthy company, the platform is easier to make software for than Linux (no matter what the market share) and will stay that way until some distro like Red Hat passes the Mac OS (not likely to happen as Red Hat has been pulling back from the desktop market lately).