Heres some interesting data from IDC about server shipments over the last five years. It includes high and low end systems.
U.S. Server Shipments
2006 - 2.87 million
2007 - 2.96 million
2008 - 2.87 million
2009 - 2.45 million
2010 - 2.95 million
Source: IDC Worldwide Quarterly Server Tracker.
Other than 2009, when the impact of the recession caused a dip, server shipments are steady. This doesnt mean that IT vendors are making less money on the hardware they do sell. The opposite has been true.
Charles King, an analyst at Pund-IT, looked at these numbers and said that perhaps the most interesting thing is how steady the numbers have been (outside of the year after the 2008 crash). During that same half decade, IT became a common factor across an ever widening range of business, consumer and communications processes globally, which suggests a continual evolution forward in server technologies -- the same number of boxes doing more and more. Some of that's ttributable to virtualization, CPU development, storage, etc.