The iPad is not a PC and Microsoft will not respond to it with Windows 7-based tablets (tablets that use the full PC version of Windows have different strengths and focus). Microsoft is too smart a firm to try an oranges to apples fight. iPad is built on a smartphone OS — iPhone OS — and not a full fat PC computing operating system. Microsoft will respond in kind.

Microsoft's real response to iPad will use a mobile-focused design. Look to the new "Metro" user interface design style for Windows Phone 7 series as a guide to Microsoft's direction. These early design mock-ups show the spacious, magazine-style typography and visual layout that carried through into the finished look that Steve Ballmer announced at MWC. Am I the only person that thinks this style would be ideal for a slightly larger device than a smartphone, like a touch screen tablet?

Microsoft has already emulated a number of parts of Apple's iPhone strategy: the new Windows Phone 7 OS limits multitasking; has no copy and paste initially; actively courts app developers; and has a centralised single distribution market for apps. Microsoft has the capability with the Windows Phone 7 series design to emulate iPad too. We can only guess Microsoft's intent, but with Windows Phone 7 series Microsoft is putting all the right capabilities in place to take its smartphone OS into other smart mobile devices, and not just further Zunes, but tablets too.

Given the current timeline for Windows Phone 7 series with the first phones launching in the second half of this year, it's unlikely that Microsoft could launch a Windows Phone 7 series tablet as well in 2010. Product strategy takes longer than that to come to fruition. Look for Microsoft's true response to iPad in 2011.

One final thing: I've been asked several times on client inquiry calls over the last few weeks to put a number on iPad sales, or the size of the tablet market, but I declined. Why? Apple's iPhone sales took off with the launch into >20 countries that came with the availability of the second iPhone model, the iPhone 3G in summer 2008. See the report Competing with Apple for the historic sales figures that demonstrate this ramp.

But while Apple has announced European availability of the iPad — UK launch lags the US by just one month, for example — Apple has yet to announce pricing outside the US. Given past sales performance of Apple products has relied upon international sales and it's not possible to forecast product uptake without knowing a product's price, it's almost completely guesswork — not even art let alone science — to make a quantitative prediction of total year one iPad product sales. Our 3 million iPad sales estimate is US-only. Other firms that try to name a total sales number for iPad are foolish.