Is Vista Sales to Business Slow?

This article in Ars Technica suggests that Vista sales to business customers via OEMs is soft.  Sales of Vista to consumers is high due to the fact that there is no consumer choice for an operating system.  Businesses, however, have different concerns when it comes to compatibility and reliability.  Hence the article reports on business customers requesting to downgrade machines shipped with Vista back to XP.  This isn't a pretty scenario for Microsoft.  The company wants to shut down XP sales for good in January, 2008.  A significant business backlash could affect that timetable.