Many because formal product names are not decided on at the time the project starts development. For example, the names for upcoming Visual Studio 2005 were not determined until less than a year ago even though development and discussions for that version of Visual Studio started over 3 years ago. This is not just a Microsoft thing, most major software companies developing vertical software products have code names during development. For example, Longhorn is the code name of the next version of Windows. Microsoft does not know what the release name will be, and probably won't know and formally decided until sometime next year. Plus, sometimes more than one version is being worked on. Like as in VS 2005 (code named Whidbey), it will be released later this year while the version of VS after that (code named Orcas) has already started in planning and prototyping. So instead of saying VS.next and VS.next.next, we say Whidbey and Orcas. Make sense? :)