It was inevitable. Microsoft's (NASDAQ: MSFT) productivity suite will finally come to Apple's (NASDAQ: AAPL) App Store, Microsoft CEO Steve Ballmer revealed at a Gartner event this week, according to The Verge. Microsoft has been looking into the possibility of an iPad version of Microsoft Office since 2010. Three years later, Ballmer himself has confirmed the project has officially found a place on the Office product roadmap.

Office for iPad
"iPad will be picked up when ... there's a touch-first user interface," Ballmer told the audience at the Gartner event. This comes as no surprise; iPad users certainly won't be using a mouse. Ballmer's comments indicated that the touch-first interface will come to its Windows version of Office first, however. Microsoft has already launched a version of Microsoft Office for the iPhone, available to paying Office 365 subscribers. But, obviously, tablets are a much better form factor for actual productivity compared to smartphones.

Microsoft is undoubtedly taking any strategic decisions regarding its Office products on tablets very seriously. Not only because the tablet market is an important and fast-growing market, but also because the company's Office products, in general, accounted for a whopping 60.5% of the companies fiscal 2013 operating income.

Why the iPad matters
Tablets, in general, are a very important market for Microsoft. Worldwide tablet shipments will outpace PC shipments in the fourth quarter of 2013 and on an annual basis by 2015, IDC projects. But ignoring the iPad, specifically, would be crazy. Because of Apple's dominance in tablets, it's difficult to get on tablets in a meaningful way without being on the iPad. In the second quarter of 2013, Apple's iPad accounted for 32.4% of worldwide tablet shipments, according to IDC. Samsung came in second (and meaningfully behind) at 18%.

However, Microsoft will be competing with several free alternatives on the iPad. Apple and Google both have free alternatives to Microsoft Office on the iPad. Apple has recently announced that iWork now comes bundled with any purchase of a new iOS device. And Google recently made Quickoffice free for iOS and Android. Quickoffice allows users to edit Microsoft Office documents with limited editing tools. It's unlikely, therefore, that Microsoft will ever achieve the same type of dominance on the iPad that the company has on PCs.

Despite its undeniably late launch and the free alternatives to Microsoft's productivity suite on the iPad, the opportunity is too big to miss. But the announcement isn't necessarily anything for Microsoft Investors to get excited about -- it's just a bittersweet announcement of the inevitable. Now investors will have to sit back and wait to see how long the company will actually take to bring Office for iPad to market.

Get great growth
Tired of watching your stocks creep up year after year at a glacial pace? Motley Fool co-founder David Gardner, founder of the No. 1 growth stock newsletter in the world, has developed a unique strategy for uncovering truly wealth-changing stock picks. And he wants to share it, along with a few of his favorite growth stock superstars, WITH YOU! It's a special 100% FREE report called "6 Picks for Ultimate Growth." So stop settling for index-hugging gains... and click HERE for instant access to a whole new game plan of stock picks to help power your portfolio.

Fool contributor Daniel Sparks owns shares of Apple. The Motley Fool recommends Apple, Gartner, and Google. The Motley Fool owns shares of Apple, Google, and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.