• by Mark Walsh  @markfwal, March 29, 2011

In a new forecast, technology research firm IDC predicts Android will become the top smartphone platform this year after vaulting to the No. 2 spot in 2010. IDC expects overall smartphone growth to drop to 50% in 2011 from 75% last year as supply starts to catch up with demand.

Overall market growth in 2010 was exceptional," stated Kevin Restivo, IDC senior research analyst. "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."

More than 450 million smartphones will ship this year, compared to the 303.4 million in 2010, according to IDC. Smartphones will also continue to outpace demand for regular cellphones, growing four times faster than the overall mobile phone business.

The proliferation of Android phones that helped drive smartphone sales last year will push the Google platform to top place in 2011, with a projected 39.5% market share. Symbian -- historically the leading smartphone OS -- will fall to second place, with 20.9%, followed by Apple's iOS, 15.7%, BlackBerry, 14.9%, and Windows Phone 7, 5.5%.

"For the vendors that made Android the cornerstone of their smartphone strategies, 2010 was the coming-out party," said Ramon Llamas, an IDC senior research analyst. "This year will see a coronation party as these same vendors broaden and deepen their portfolios to reach more customers, particularly first-time smartphone users."

Samsung, HTC, and Motorola are among the manufacturers that have benefited most by selling Android-powered devices.

The research firm expects the strategic alliance between Nokia and Microsoft will help both get back into the smartphone race as Windows Phone 7 surges to become the No. 2 mobile operating system by 2015. IDC predicts WP7 will claim 20.9% share by then, ahead of iOS (15.3%) and BlackBerry (13.7%), but still trailing Android's 45.4% share by a wide margin. Symbian will have all but disappeared by 2015, with just 0.2% share, in the wake of Nokia shifting to WP7 as its main smartphone platform.