In other words, users shouldn't expect an Office 2014 or Office 2015, but small-step changes to Office 2013 over the next three years.
But even those will mark a major change in how Microsoft works on Office. And while some customers may relish frequent updates and upgrades, others will certainly not.
"There are a lot of organizations that are not used to that pace, and cannot keep up with that quick a cadence," said Silver.
In an interview this week, Paul DeGroot of Pica Communications, and an expert in Microsoft's licensing practices, said that it often takes enterprises three years or longer to migrate their machines to a new edition of Office, and because of that, they often skip one or even two of the following upgrades.
"If organizations cannot adapt [to a faster release cycle], they may think, 'Well, let's go with Google [Apps]. That may be on a fast release cycle too, but at least it's cheaper,'" said Silver.
Microsoft has made allowances for conservative organizations, however, as they can use their existing management tools—presumably including Windows Server Update Services (WSUS)—to limit Office 2013 updates to those that have been tested and verified as compatible with existing software and practices.
It's unclear whether companies and consumers who stick with the traditional perpetual licenses for Office—rather than shift to subscriptions—will also receive the same updates.
Silver thought that some will, especially businesses making Software Assurance payments, an annuity-like program under which volume license customers fork over annual fees for the rights to all upgrades of a specific product.
"I think Microsoft will use [the faster release cycle] as another differentiator for subscribers," said Silver. "But folks with [Software Assurance] will eventually get the updates, just not in real time."
Directions on Microsoft's Miller expects that Microsoft will announce the contents of Office 2013 updates only when they're ready for release, rather than tout them beforehand, as they have done during the old-school three-year release cycles.
But in the end, Miller was dubious of anyone who dwelled on Office's accelerated development. "If they're buying [Office 365] for the faster updates, they're buying it for the wrong reason," Miller said. "They're looking at the cup holder rather than the whole car. There's so much more win inside the product than this."
This story, "Microsoft: We can update Office-by-subscription every 90 days" was originally published by Computerworld.