Though Microsoft chairman Bill Gates never referred to Whistler as Windows 2001 during his Comdex keynote, a Microsoft press release about the event, which was written before Gates appeared on stage, says, "\[Gates\] explained that cutting-edge hardware and software companies are excited and already planning for the Windows 2001 launch." Gates briefly referred to Whistler a couple of times during the speech, though he never really demonstrated the product directly. A prototype version of the company's forthcoming TabletPC device, however, was running Whistler.
Here's the full quote:
"Gates said that the next version of Windows, scheduled to be available in the second half of next year, will make the PC much simpler for consumers and business users alike, while featuring the rock-solid performance of Windows 2000 that businesses have relied on. He explained that cutting-edge hardware and software companies are excited and already planning for the Windows 2001 launch.