The whole area of virtualisation whether for servers and or the desktop, is complex and particularly technical. As a result there will be costs associated to this as it will require a specialist company in order to implement, install and support such a system. As a result, you must make completely sure that the benefits outweigh the potential costs.
Virtualisation is of particular value to larger companies with many employees and multiple servers. That aside, there are some excellent systems for the smaller business but care and diligence should be taken before making a purchase order. Finally, while the view has been expressed that virtual desktop environments are more often than not useful for large scale companies, there is still a place for this technology within the sole trader and SME but ensure that you cover all of the bases!