It's complicated. That's the best way to describe the relationship between Microsoft and platforms other than its own Windows when it comes to its super-popular Office productivity suite.

While on the one hand offering Office, with its word processing, spreadsheet, presentation and e-mail programs for mobile devices like Apple's iPad would vastly expand its popularity, it could also reduce demand for Microsoft's signature product, its Windows operating system.

What's Taking So Long?

The Redmond, Wash.-based tech giant's vice president of marketing suggested this week that it could be some time before you can tap out a Word document on the screen of your iPad or Galaxy Note or crunch some numbers via Excel.

Speaking at the Goldman Sachs Technology and Internet Conference, Tami Reller stressed that Microsoft is still deliberating its best interests in the matter.

"You'll see us be thoughtful about how and when we bring what applications to what platforms," she was quoted by Computerworld as saying in response to a moderator's question. She added, "We come at it from that angle, which is, 'What businesses do we need to drive forward?' That's how we will make the decision."

Nearly four years after Apple created the tablet market with the iPad -- heavily driven by apps that make it not just easily portable but more fun and useful -- it seems surprising that Microsoft is still contemplating this question.

"The fundamental issue for Microsoft today is determining its mobile strategy," said tablets expert Jeff Orr of ABI Research. "With the upcoming integration of the Nokia Devices team and a new CEO at the helm [Satya Nadella], ABI Research believes the decision to embrace iOS and Android with the full Microsoft Office suite of apps is still a ways off."

Orr noted that Microsoft already offers Office 365 as a subscription service to view and edit content through a Web browser. "This permits use of mobile devices, though the level of productivity in the browser could limit the usability on a tablet or smartphone," he told us.

Size Matters

It remains to be seen whether the right mobile device for optimal use of Microsoft Office has hit the market. After all, smaller screens limit navigation of an Excel spreadsheet, and forget about trying it on a smartphone.

"One of the trends in 2014 is experimentation with larger-display tablets, such as 12- and 14-inch, to see if there is a market audience that has interest," Orr said.

"Notably, the recent launch of the Pro series tablets in Samsung's Galaxy Tab and Galaxy Note families shows some of what can be done with a 12.2" display, including running multiple applications in up to 4 separate views, as well as the use of the S-Pen along with a Bluetooth mouse to provide a docked tablet experience like a 2-in-1 ultraportable PC."