[citation][nom]spookyman[/nom]I doubt you will see Apple ever eat into the Microsoft's 95% of OS share on the PC market. Microsoft's biggest buyer of their products happens to be corporations.[/citation]
I hate to tell you this, but Apple is, and has been taking market share from Microsoft for quite some time. There was a time they were less than 2%, but year after year they keep eating Microsoft alive. My guess is they will keep doing it for a few more percentages, because Apple never wants a big market share (because it implies a price that would allow that), but even the 4% or so Apple has taken from Microsoft hurts, bad. That's 4% of a HUGE market, and the trend keeps continuing, even as the PC becomes a smaller component (with tablets and smart phones taking up a greater portion the last few years) of the market.
I would expect Apple's top market share to be around 10%, maybe less. But, with smart phones and tablets, a place Microsoft can't compete in, it's clear Apple is gaining in a lot of directions.
Without Jobs though, it might reverse. Tablets might fade like netbooks. iPhone is probably safe for a while, but without Jobs it may lose what makes it special, and lose market share. The Mac seems the safest, since it's very reliable (wins year after year), very attractive (I saw a server today, and thought how attractive it was, and then saw the Apple logo. They just get that part right), and also has huge "chic" appeal to hipsters.
Microsoft has nowhere to go but down. In processors, we have excellence. In OS's, we have Microsoft's pathetic, bloated, buggy rubbish, or Apple's overpriced, Unix-based, also bloated, rubbish. We need a third party. It's hard to enter, but the competition is really weak.