What's in a Codename?
The origins of Microsoft product codenames is a fascinating topic. For example, Burton (Microsoft's internal name for Team System) is named after a snowboard company. Longhorn, the next version of Windows is named after the Longhorn Saloon & Grill at the foot of Whistler mountain in BC.
Chris Bowen recently posted a nice guide explaining all of the Team System codenames. Here is another comprehensive list of Microsoft product codenames.