Tablets expected to surpass desktop, laptop sales by 2015

The momentum behind tablets can't be contained, with sales expected to top the combined desktop and laptop market by 2015.

That's according to Gartner, which released a study today looking at tablet, PC, mobile device sales. Total worldwide sales of all the devices are expected to hit 2.4 billion units this year and grow to just under 3 billion by 2017.

The release of several high-profile -- but low-cost -- tablets and the expansion of their capabilities has only accelerated the adoption of tablets at the expense of the traditional laptop and PC business. By 2015, unit tablet sales are projected to come in at 337.8 million, eclipsing combined desktop and laptop sales of 292.2 million, according to data supplied by Gartner to CNET.

The numbers underscore a broader shift away from traditional computers and toward more mobile devices. Android is already the leading operating system, surpassing Windows and a combination of iOS and Mac, and Google's OS is expected to further widen its lead over the next four years.

Despite an assault on its core PC business, Microsoft is also expected to continue growing, albeit at a much slower rate. The company has tried to make inroads into the tablet business itself, notably with the Surface, as well as foster more Windows tablets with its Windows RT variant of its OS. Both initiatives have seen mixed success, with Windows RT devices performing particularly poorly.

The mobile phone business, which is also seeing its slow growth, will continue to outsell the other categories combined. Gartner estimated that 1.8 billion mobile phones will be sold this year, with the market growing slightly to 2.1 billion by 2017.

Correction 8:23 a.m. PT: This story originally gave incorrect figures for device sales projections. Gartner expects that by 2015 unit sales for tablets will hit 337.8 million, while combined desktop and laptop sales will be 292.2 million.