I think business users generate more money. And business users want the desktop.
Humungous amounts of business users live permanently in Outlook, they couldn't care less about the desktop if they tried. Even more have moved much of their LOB apps over to web applications. If they system can provide a very simplistic method of accessing those applications and really only require users to be trained in using the applications, rather than also have to provide Operating System training (as is the case today), then there is certainly an enormous potential benefit in moving to Windows 8.