To paraphrase Mark Twain, the death of the mega OS release has been greatly exaggerated, Microsoft’s chief operating office said this week.

In a part-speech, part-presentation at the Worldwide Partner Conference (WPC) in Denver, COO Kevin Turner echoed comments made earlier this year by CEO Steve Ballmer that Windows Vista is not the last major update of the company’s client operating system. Tuesday, as Turner dubbed Vista and the simultaneously-unveiled Office 2007 “huge, big dog releases,” he also promised more would come.

“Certainly, this last year has been an unprecedented year for Vista and Office and the launch,” Turner said. “And we are still committed to the desktop. There will be another release and launch of a Vista-type operating system. [And] there will be another release of Office.”

Turner’s assertions parroted those made by Ballmer Jan. 29, just before Vista and Office 2007 went to retail. In New York on the launch eve, Ballmer said Microsoft had “plenty more where that came from,” referring to Vista and its follow-on. At the time, speculation had mounted over whether Microsoft would, or even could, again mount a Vista-sized effort, in part because Ballmer himself had sworn that the company would never again take five years to craft a new OS.