Microsoft has lagged in the fast-moving smartphone market as Apple's iPhone and Google's Android OS have captured the limelight. IDC's report showed about 16 million Windows Mobile devices shipped in 2009, with a forecast of 22 million this year and 32 million next year. Windows Mobile is in fourth place among phone operating systems, behind Symbian, BlackBerry and Mac OS X, and will remain there until 2014, when it will surpass Mac OS X, IDC believes.

, a significant departure from today's Windows Mobile OSes, showed promise in demonstrations at the Mobile World Congress trade show in February, Stofega said.

"The first step was to ... redo Windows Mobile so it was more responsive, better (user interface), everything everyone complained about, and more up-to-date with the competitors," Stofega said.

IDC commented on those demonstrations in its report but did not go so far as to forecast sales specifically for the future product.

"Now they have to ship, and they have to get (Windows Phone 7) into the hands of their OEM partners quickly, and that's the challenge," Stofega said.