yes, any game with dx10 features will require vista to make use of these features, since dx10 is vista only. You'll find the dx10 features most likely will offer little visual difference over dx9 counterparts, although performance hit with said items being turned on should be less from what MS have said about vista. Although currently the performance hit by using vista over XP is the opposite of this, but drivers&OS will have matured by time game is out, hopefully anyway.