That leaves little room for interpretation.

But Wes Miller of Directions on Microsoft, and that research firm's in-house lead analyst on Office, was not so sure. In fact, Miller said there were compelling arguments for either issuing native iOS Office apps, or keeping the money-making suite tightly -- if not exclusively -- tied to Windows.

It's conceivable, said Miller, that Microsoft would link iOS Office apps to its upcoming Office 365 subscription plans, which in the case of the deal for consumers, lets customers install Office on as many as five devices, including desktop and notebook PCs, tablets, and smartphones.

In that arrangement -- and Apple's iOS App Store policies seem to allow this -- Microsoft would offer Office apps free-of-charge, then tie them to an Office 365 subscription. Only users with a current subscription would be able to actually run such apps.

Other software-as-a-service companies use that model for their iPhone and iPad apps, which access customers' accounts: Salesforce is one example.