It’s a mobile world after all, even where PCs are concerned. Canalys today published its latest figures tracking PC sales in Q4, and thanks to the strength of the iPad — and Canalys’ decision to count tablets as ‘PCs’ — Apple has once again kept its position at the top, taking 19.5% of all sales, or just under 31 million units. Not counting tablets, Canalys says that PC shipments would have declined 7% compared to Q4 2012 — “with falls in all regions” — but with tablets, sales were up 17.9%.

In contrast to laptops, netbooks and desktop computers, tablets continue to explode in popularity. Tablets alone accounted for 76.3 million units shipped, or nearly half of the whole PC market — 48.3% to be exact. That represents growth of 65.2%.

In fact, at the current rate it looks like Alex’s guess, that tablet sales/shipments may outstrip PC sales by Q2 2014, may well come to pass.

For Apple, its position as a leader in PCs is almost entirely down to the success of the iPad. Shipments of non-tablets like the MacBook were just under 5 million units, with iPad tablets, accounting for 84% of its shipments.

And while in quarters past Android-based devices have encroached on the iPad market share, this past quarter Apple surged again, and now has 34.1% of the overall tablet market, “the launch of the iPad Air and iPad mini with Retina display providing a much needed boost.” Also helpful: a reduction in price for the original iPad mini to $299 in the U.S.

That’s not to say that Android is fading from view anytime soon. As Canalys points out, Lenovo — which ranks as number two in PC shipments with just under 12% of the market in Q4 — “was early to embrace Android as a tablet OS, while the likes of HP and Dell waited for Windows 8 and prioritized margin over volume.” And that has been a large part of its success.

“Lenovo still has the potential to grow its global notebook shipments and has emerged as a challenger in the tablet space,” writes James Wang, Canalys analyst. He says that worldwide Lenovo shipped three times as many tablets in Q4 as HP and Dell combined.

Overall, Lenovo’s PC shipments grew 25.5%, but although it had an 11.7% decline in notebooks in key markets like China, EMEA shipments were up 30.4%.

While Samsung is now the world’s largest handset maker, the story is different when it comes to PCs. It remains in number-three position, even when factoring in tablets. The Korean maker shipped 18.2 million units, with tablets taking nearly 80% of that share, or 14.5 million units (a rise of 90% over a year ago). “Samsung is a clear second in the tablet market,” Canalys writes.

One thing that Canalys points out here is the big difference between shipments and sales. It seems to imply that some of what counts as shipments may look like a strong position, but when it will come down to sales the chickens may come home to roost. “Samsung’s shipment growth came at a price, as it had to resort to significant promotional activity to run down inventory,” Canalys writes.

Another big question is how device makers will deal with price competition. Apple continues to push devices at the premium end of the market, but with Android tablet makers selling feature-rich devices at lower prices this will continue to wipe out whatever brand equity Apple may have. “Apple is focusing on China, where it has a 38.3% share of the tablet market, but it does not reach competitive price points in other high-growth markets and risks missing out on future progress,” writes Tim Coulling, a senior analyst with Canalys. “Product innovation and competition in the Android camp will continue to accelerate. This gives good growth potential to smaller local players and those top-tier vendors willing to disrupt margins in the tablet space.”

And what about the traditional mainstay of the PC market, Windows? Canalys writes that commercial demand for PCs is “improving” as PC owners upgrade from Windows XP and subsequently need to get new devices. “But Windows 8 will not be a major beneficiary as many businesses will take the safer option of moving to Windows 7,” Canalys writes. “Windows 8 uptake remains weak and the PC refresh cycle shows no sign of returning.”

The hope, then, is for Windows 9, reportedly scheduled for April 2015. Otherwise, “Microsoft risks losing momentum unless it does something drastic to turn its Windows business around” because the inevitable is appears to be happening: Just as Android disrupted the ecosystem that traditionally had Nokia at the top of the pyramid, so too is Google threatening to do the same in PCs. “Consumers are becoming more open to Windows alternatives, and Google’s low-cost options are reaping the rewards,” writes Pin Chen Tang, another Canalys analyst. “Android is now the most popular OS in the tablet segment and PC vendors are showing a keen interest in Chromebooks, which are carving out a niche, especially in the education sector.”