IDC: Windows Phone to overtake iPhone sales by 2015 ... What do you think?

According to research group IDC, worldwide sales of Windows Phone handsets will exceed that of iOS devices by 2015.

According to IDC, the smartphone market is expected to grow 49.2% in 2011 as more consumers and enterprise users exchange feature phones for smartphones, with this helping to smartphone vendors to ship more than 450 million smartphones in 2011 compared to the 303.4 million units shipped in 2010. IDC also predicts that the smartphone market will grow more than four times faster than the overall mobile phone market.

"Overall market growth in 2010 was exceptional," said Kevin Restivo, senior research analyst with IDC's Worldwide Quarterly Mobile Phone Tracker. "Last year's high market growth was due in part to pent-up demand from a challenging 2009, when many buyers held off on mobile phone purchases. The expected market growth for 2011, while still notable, will taper off somewhat from what we saw in 2010."

 IDC also predicts (guesses) that Windows Phone will jump to second place, beating iOS:

Nokia's recent announcement to shift from Symbian to Windows Phone will have significant implications for the smartphone market going forward. "Up until the launch of Windows Phone 7 last year, Microsoft has steadily lost market share while other operating systems have brought forth new and appealing experiences," added Llamas. "The new alliance brings together Nokia's hardware capabilities and Windows Phone's differentiated platform. We expect the first devices to launch in 2012. By 2015, IDC expects Windows Phone to be number 2 operating system worldwide behind Android."

Here's a handy chart showing how things might change:

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