The biggest loser of this shift in core CPU usage is plain Linux.
People buying x86-compatible hardware did, until yesterday, have two choices: Windows or Linux. Windows came with the greedy hand of Microsoft, Linux came with the nerdy hand of an army of old-school hackers who couldn't agree on which hand to wipe their a55 with if their life depended on it. Now users have a truly viable alternative: the userfriendliness of OSX.
I predict a devastating blow to the market share of plain Linux, and a tremendous increase in productivity to get open source applications ported to OSX. No more arguments about Gnome or KDE, either: it will be OSX's GUI first, and the rest later. And who needs the rest save for those who want to be different and not want to think like the crowd? The role of Linux will dwindle, save for a testing ground for old schoole hackers who shun the idea of capitalism and monoculture. Within years, Linux will be once again stuck in the dark, fiery caves where it was forged all those years ago. It will be tended to by a small contigent of loyal fundamentalistic priests.
On the other hand, given the prolific rise in availability of open source applications which, thanks to OSX's Unix core, will compile effortlessly without too many changes, will have senior Microsoft execs wetting themselves for many months and years to come. Linux was viewed as a potential threat, more-or-less-ignored-but-still-in-Bill's-Book-of-Bad-Stuff; Apple on i86 is much, much worse; probably written down somewhere in Bill's-Book-of-Nightmare-Scenarios.
Of course, this is all provided Apple can succeed in the move from PPC to x86. Which I am quite sure will happen without too much trouble. Loyal fans have nowhere to go, and even they must realise the tremendous potential of this idea. Steve Jobs has not been smart over the years; this move however, is majestic.
