Here's some interesting information I found:
Windows Vista is the name of the latest release of
Microsoft Windows, a line of graphical
operating systems used on
personal computers, including home and business desktops,
notebook computers, and
media centers. Prior to its announcement on
July 22,
2005, Vista was known by its
codename Longhorn. As of
November 8,
2006, Windows Vista development is complete and is now in the
release to manufacturing stage;
Microsoft has stated that the scheduled release dates are currently
November 30,
2006 for volume license customers and worldwide availability on
January 30,
2007.
[1] These release dates come more than five years after the release of
Windows XP, Microsoft's current consumer and business operating system, making it the longest time span between major releases of Windows.