From RedmondMag.com: Microsoft Math
A very interesting and well-written article analyzing Microsoft's track record on meeting shipment dates.
It shouldn't be news to anyone who has dealt with or followed Microsoft for any length of time that the company is notorious for missing ship dates. But with another major operating system upgrade on the horizon in Longhorn, it's a good time to take a hard look at the company's track record to try to glean tendencies that can help customers plan accordingly.
To do that, Redmond magazine researched announcement dates and delays for Microsoft desktop and server operating systems, along with Microsoft Office and Exchange products going back as far as 1983. We took the resulting data and handed it off for analysis to Barry Bayus, a professor of marketing at the Kenan-Flagler Business School at the University of North Carolina. Bayus co-authored a 1999 report titled, "Truth or Consequences: An Analysis of Vaporware and New Product Announcements," and thus has expertise in missed product ship dates.
The result picturing isn't a pretty one. After tallying up all the numbers, we found that, on average, Microsoft ships its desktop OSes 10 months late while its server OSes are just over a year late. The track record for major, mold-breaking OSes, however, is much worse. Windows 95, for example, was 14 months late, while NT Server 4.0 was 21 months late—nearly two years.
It's the mold-breaking products you should likely keep in mind when trying to assess when Longhorn might ship, because it's Microsoft's most ambitious operating system in years—or at least, it was before the company began stripping out key components like WinFS, a step the company took solely so it could hit a reasonable ship date.