I aksed this question for Fusion 4 way back when
http://communities.vmware.com/message/1995669#1995669
Now with Fusion 5, they have changed the nomenclature a bit, but I would still love to not have to answer this question every time I want to revert my snaphot.
Please have some sort of Power User setting to disable this prompt or always have it know that NO, I do not want to save a snapshot when I revert to a previous.
-Trey