The number of tablets shipped from manufacturers more than doubled over the last year, according to a report from IDC. They reported 49.2 million tablets were shipped in the first quarter of 2013 - more than in the first half of 2012. Apple remains the top manufacturer, accounting for 19.2 million units, followed by Samsung. Microsoft entered the Top 5, shipping some 900,000 of its Surface and Surface Pro tables, but still being outgunned 2-1 by Amazon's Kindle Fire tablet.
However, with multiple tablet models and manufacturers using the Android operating system, it's been gaining share from Apple' In the last quarter (1Q13), 56.5% of the units shipped ran on Android OS, compared to 39.6% running Apple iOS - a virtual flip in positions from the first quarter of 2012. Windows operating systems cracked the tablet market, with the Windows and Windows RT OS installed on a combined 3.7% of the tablets shipped.
Source - Android Tablets Edge Out iPad: IDC, Information Week