IDC has raised its forecast for 2012 tablet shipments due to great expectations for Apple’s iPad, which IDC expects to increase market share, despite Microsoft launching tablets later this year.

The research company, which is related to Macworld publisher IDG, expects that the worldwide market for tablets will reach 107.4 million units this year. The previous forecast was for 106.1 million units. IDC predicts that next year the market will extend to 142.8 million tablets and 222.1 million by 2016.

IDC says Apple's iPad could take 62.5% of the market this year (it was 58.2% in 2011). Android will not fair so well: Google’s share of the tablet OS market will slip to 36.5% this year, from 38.7% in 2011, according to IDC.

As for Research In Motion's (RIM), its BlackBerry tablets will slip to 1% of the market this year from 1.7% last year, predicts IDC.

"Apple's iPad shows few signs of slowing down," IDC analyst Tom Mainelli said, noting that Apple’s decision to continuing to offer lower cost iPad 2 devices is "paying off”.

"The addition of the Retina Display and 4G capabilities to the third-generation products clearly enticed many current owners to upgrade. And Apple's decision to keep two iPad 2s in the market at lower prices—moving the entry-level price down to $399—seems to be paying off as well,” he said.

Mainelli added a further prediction, suggesting that: "If Apple launches a sub-$300, 7-inch product into the market later this year as rumored, we expect the company's grip on this market to become even stronger."

IDC's figures do not include the upcoming Windows 8 and Windows RT tablets, but the analysts note: “We don't expect Windows-based tablets to necessarily take share from Apple and Android, but will grow the overall tablet market."

"Our current thinking, based upon early pricing expectations for these products, is that Windows-based tablets will be largely additive to our existing media tablet market forecast,” Mainelli added.