According to Forrester Research, Windows vista is the 'New Coke' of Operating Systems.  After being on the market for over a year it still hasn't captured 10% of the enterprise space according to Enterprise Trends: Vista Is Rejected; Mozilla And Apple Make Small Gains by Thomas Mendel, Ph.D.  Other fun facts for Microsoft's flagship operating system:

• 8.8% Vista Penetration
• Microsoft says it has sold 180 million licenses (including downgraders)
• The share of Macs grew to 4.5% in June from 3.7% in January 2008
• Linux's share of desktops, meanwhile, fell significantly, to 0.5% in June from 1.8% in January
• 19.4% of enterprise users are using Firefox, up from 16.8% at the beginning of the year. Meanwhile, Microsoft Internet Explorer's share only slipped slightly, from 79.1% in January to 77.6% at the end of June.
• Both Flash and Java were nearly ubiquitous. Flash Player Version 9 was on 97% of desktops, while Java was on 99.9% of them. But application developers shouldn't try too hard to jazz up their apps with Flash elements -- "business users don't want to hunt for navigation nor do they crave excitement," Mendel wrote.
• Forrester also discovered that despite ever-increasing screens and screen sizes, the largest slice -- 34.1% -- of business users are using screens between 15 and 17 inches in size with resolutions of 1,024-by-768 pixels; another 25.2% use screens between 17 and 19 inches in size with resolutions of 1,280-by-1,024 pixels.