A recent TDWI survey asked people "What do you think a data warehouse appliance is?"  It is interesting that 53% of respondents replied that a data warehouse appliance is "server hardware and database software built specifically to be a data warehouse platform".  Also interesting is that only 19% answered that they don’t know.  These results again point to how data warehouse appliances are becoming much more mainstream and adoption is picking up.  You can read more about the survey in Philip Russom’s article "Defining the Data Warehouse Appliance" http://www.tdwi.org/Publications/display.aspx?id=7784.