Here is another example. Maybe shuttle will use Vista Ultimate.
http://www.infosyncworld.com/news/n/6521.html Among the first media PCs to incorporate Intel's new Viiv platform, Shuttle offers a sneak peek of its new ultra-small form factor XPC X100 and the rack-sized XPC
Hardware requirements and recommendations for the Windows Vista Capable XPCs have been selected to ensure that XPC systems and components that fit these criteria will run Windows Vista and will enable the next generation of Windows applications.
The Windows Vista Capable XPCs allow you to the transition from Windows XP to Windows Vista. Windows Vista Capable XPC reassures your investments will retain its value after Windows Vista is available.