With iPad 3, Apple could ship more PCs than HP

According to new estimates by analyst firm Canalys, Apple (s aapl) could sell more PCs than current market leader HP (s hpq) during the first half of 2012. The key to Apple’s market dominance, however, is counting the category-busting iPad in addition to Mac sales.

The tipping point might come sooner, but Canalys thinks the launch of the iPad 3, expected sometime in the first or second quarter of 2012, will be the key to really putting Apple’s total shipments over the edge, propelling it from its current second-place spot to first overall.

Canalys estimates global PC shipments will reach 415 million units worldwide by the end of 2011, an increase of 15 percent year-over-year, thanks in large part to tablet sales. In North America, shipment growth is predicted to be up around 18 percent compared with 2010, with all but one percent of that growth coming from tablet sales, and in Europe, without tablets, PC sales would actually be down from last year.

Apple recently crossed the five-percent mark in terms of the global PC market, when only considering Mac sales, according to Charlie Wolf of Needham. It happened thanks to 22 straight quarters of Macs outperforming the general industry, with 43.8 percent growth year-over-year during the last quarter alone. With Mac sales growing, and Apple’s continued domination of the tablet market, it’s no wonder Apple will soon be on top of the game when you count the iPad among its PC offerings.

Some may see counting the iPad alongside PCs as something of a cheap move, but it actually makes a lot of sense. With the global PC market facing flat or negative growth, and tablets stepping in to replace traditional computers for a lot of use cases, it’s probably better to count them here than in any other grouping.

While Apple has a significant advantage now in terms of the iPad when it comes to tablet shipments, Amazon (s amzn) and Barnes & Noble (s bks) are shaking up the low end of the market with their respective Android slates, too, so it’ll be interesting to see how those devices chart going into 2012. Who knows? Maybe Amazon will eventually become a top PC manufacturer, at least according to scoring from firms like Canalys.