As for online delivery, Helm said Microsoft's strategy is to come up with complimentary services, not mutate Office into online applications. "They've continued to come up with services," he said. "Even Office Online has some, like a calendar-sharing service. It's free, unlike Office Live, and its purpose is to encourage people to use the most recent version of Outlook."

Outlook 2007's calendar can be shared using Office Online. Previously, an Exchange server was needed to publish shared calendars. "We might expect to see more of that," said Helm.

Microsoft executives have fielded similar questions about Windows and its future, brought on by delays in Windows Vista, which was released more than five years after its predecessor, Windows XP. Microsoft CEO Steve Ballmer has said several times in the past few months that the company will never again take that long to upgrade the operating system.

Although Office's upgrade cycle has historically been much shorter -- three years is Microsoft's goal, Raikes said -- the suite is under pressure from quarters such as , a US$50-per-year per-seat hosted online application bundle that debuted last month.

"What must be scary to Microsoft isn't the idea of wholesale replacement of Office [by enterprises], but that there are lots of people in an organization who just don't need Office and who can get along with something like Google or OpenOffice.org," Helm said. "If that catches on, enterprise might drop their Office site license. That's when it becomes a serious threat."