Phone manufacturers officially begun selling Windows Phone 7 devices in the U.S. this week, less than a year since Microsoft revealed the ground-up redesign of its platform and started pushing the idea of a simpler mobile experience. But perhaps Redmond’s It’s far too early to forecast another “Kin” failure, though. Microsoft generally gets into new markets for the long run and is prepared to burn a lot of cash to position itself in the market – it persevered with the now profitable Xbox, and less successfully with other ventures such as Zune and Bing. With Apple and Google raking in billions from their mobile platforms, we’ll likely see Microsoft sticking around for the fight. It might just take some time to shake off the Windows Mobile stigma.