Will tablet computers one day outsell traditional personal computers? Almost certainly. Has the iPad made Apple the most important personal computer vendor on earth? Most definitely.While Apple is introduced a new version of the iPad Wednesday in San Francisco, however, the real shift has already happened. Smart phones outsold personal computers for the first time last year.And there’s no reason to think Apple’s iPad is about to start cannibalizing those. One might even consider the iPad — which relies on a smartphone processor and smartphone software — a sort of smartphone.More than 487.7 million smart phones were shipped last year, up 62.7% from prior year; according to tech tracker Canalys. Just 414.6 million personal computers — including tablet computers — shipped during the same period, up 14.8% from the year earlier. And most of that growth came from tablet computers.Read Connie Guglielmo’s live blog of Wednesday’s Apple event.Canalys figures tablet sales grew 274.2% to 63.2 million units — most of them iPads — last year. Sales of desktop computers grew just 2.3% to 112.4 million units; notebook sales grew 7.5% to 209.6 million units, and netbook sales collapsed, falling 25.3% to 29.4 million units.That’s led observers to predict tablets will soon begin outselling traditional personal computers. Assuming, among other things, that Android and Windows tablets will begin selling well next year, Horace Dedieu at Asymco thinks tablet computers will begin outselling PCs in the fall of next year.No one at Apple is likely to argue with him. “From the first day it shipped, we thought–not just me, many of us thought at Apple–that the tablet market would become larger than the PC market, and it was just a matter of the time that it took for that to occur,” Apple Chief Executive Tim Cook said at an investor conference earlier this year.How can Cook be so confident? Consider this: Apple sold 72.3 million iPhones, 32.4 million iPads, and more than 21.3 million units of Apple’s iOS-powered iPod Touch* (assuming, conservatively, that the Touch accounts for half of all iPod sales). That’s at least 126 million units, and growing; 14 million more than the 112.4 million desktop PCs sold last year.In other words, Apple has already forced a profound shift. Computers that rely on mice and keyboards have been eclipsed by the more mobile, more connected computers Apple has been pushing for years.*Yes, I know Apple styles this product as the ‘iPod touch,’ however since the product name is a proper noun I figure there’s got to be a capital letter in there somewhere, or things get confusing when discussing the iPod Touch in the context of touch-screen devices in general.