Microsoft's Windows Mobile OS will regain some of the smartphone market share it has lost recently \u2014 but will still be in last place in 2014, according to research firm IDC's Worldwide Quarterly Mobile Phone Tracker.This isn't necessarily bad news for Microsoft; any growth is cause for celebration given that Redmond has been pushed to the back of the smartphone line behind mobile young guns Apple (iPhone) and Google (Android). "Android and iOS have taken away both mindshare and market share from the old regime [BlackBerry, Symbian, Windows Mobile], and have helped propel the market forward," says Ramon Llamas, senior research analyst with IDC's Mobile Devices Technology and Trends team.Yet on the plus side for Microsoft, IDC is forecasting Windows Mobile to grow in the next five years while key rivals lose market share. Though one rival, Google's Android mobile OS, will gain more market share than anyone. Microsoft is releasing Windows Phone 7, an overhaul of its mobile OS, this fall.Windows Mobile's worldwide market share is currently only 6.8 percent, according to IDC, but it will grow by 43.3 percent in the next five years, to reach 9.8 percent of the smartphone market by 2014. In the same time period, BlackBerry's share will decline by 3.5 percent, from 17.9 percent to 17.3 percent, and the iPhone's share will decline by nearly 26 percent, from 14.7 percent to 10.9 percent. By 2014, the iPhone will have only an estimated one percent market share lead on Windows Mobile devices, according to IDC.The entire mobile device market is expected to grow by 55.4 percent this year compared to 2009 (measured by the number of phones shipped). This is a 10 percent higher estimate than the one IDC issued in its last Mobile Phone Tracker. For 2010, IDC expects mobile device vendors to ship 269.6 million smartphones, compared to the 173.5 million units shipped in 2009, a year in which the market declined 2.8 percent, the first such occurrence in IDC's Mobile Phone Tracker history. \n\nWindows Phone 7: 3 Reasons It's Not Just for Consumers\nWindows Phone 7: Enterprise Adoption Not a Sure ThingWindows Phone 7 Reviews: Beauty or the Beast?\n\nThe catalyst for the increased volume this year is the launch of new models in recent months, such as the BlackBerry Torch, the iPhone 4 and the EVO 4G, according to the IDC report.The momentum will continue in 2011, with IDC expecting the smartphone market to increase the number of phones shipped by 24.5 percent next year. But it will decline after that, and by 2014 the market is expected to grow by only 13.6 percent.Though Windows Mobile will see market share growth, the big winner for the next five years will be Android phones, which IDC predicts will increase market share from 16.3 percent to 24.6 percent, a 51.2 percent jump."Phone vendors have been drawn to Android because it allows them to present their own approach to what a smartphone experience can be," says IDC's Llamas. "And users have quickly warmed to Android, comparing it to Apple's iOS due to its ease of use and a growing mobile application storefront."While Microsoft is predicted to still have the lowest worldwide market share in 2014 behind iOS, BlackBerry, Android and Symbian, IDC emphasizes that there is room for all smartphone players to grow and compete, with no one vendor taking over as the market share king the way Microsoft has with Windows on the PC."The smartphone OS market will remain fragmented but healthy for the foreseeable future," says Kevin Restivo, senior research analyst with IDC's Worldwide Quarterly Mobile Phone Tracker.Shane O'Neill covers Microsoft, Windows, Operating Systems, Productivity Apps and Online Services for CIO.com. Follow Shane on Twitter @smoneill. Follow everything from CIO.com on Twitter @CIOonline. Email Shane at email@example.com.