Traditional PC shipments are set to decline in 2012 for the first time in over a decade while sales of mobile computing devices such as smartphones and tablets continue to increase and cannibalize PC sales. Even so, there are expected to be 1.5 billion devices running Windows by the end of the year, compared to 608 million using Android. The latest numbers from Gartner Research paint an interesting picture, however, suggesting that Google’s (GOOG) operating system will soon be on more computing devices than Microsoft’s (MSFT) according to Reuters. At the end of 2016, the total number of computers, smartphones and tablets running Android is estimated to reach 2.3 billion units, compared to 2.28 billion Windows devices. While Microsoft’s operating system has dominated the market for the last two decades, the company has struggled recently in the growing mobile space.