Tablets have swiftly become one of the world's fastest-growing categories of consumer electronics. We forecast global tablet shipments to grow +250% YoY in 2011. From a worldwide market of precisely zero in 2009, tablet volumes will approach 100 million units by 2013.

Which operating system vendors are driving the hyper growth?

First, of course, is Apple iOS. Apple popularized the finger-driven touchscreen-tablet segment with the launch of its iPad in the first half of 2010. Attractive hardware design, user-friendly software and a well-stocked apps store was enough to ignite demand among consumers and businesses for tablets. We expect Apple to make up 6 in 10 of the total global tablet market this year.

Second, Android has emerged as the main credible challenger to iOS's leadership. Samsung was the first famous brand to challenge Apple, and it has been followed recently by Amazon. Amazon will undoubtedly elevate Android shipments in the coming weeks because its competitive pricing and compelling ecosystem of apps are broadly equal to Apple's. We expect Android to make up 4 in 10 of the total global tablet market this year.

Third, there is a long tail of "strugglers". Namely, Microsoft Windows, Blackberry OS and webOS. Microsoft is not optimized for finger-touch usage, Blackberry OS was mis-launched without native messaging on the PlayBook, while webOS failed to excite developers or consumers.

Of those three "strugglers", Microsoft stands the best chance of turning into a "challenger" at the moment. Microsoft's deep pockets and Windows 8 upgrade give it a chance to become the third major OS in tablets in 2012. If Microsoft can get right the launch of W8 next year, the tablet OS wars will become frenzied.