This first comprehensive review of the emerging field of PetaFLOPS computing systems produced a number of important findings that broadly define the challenge, opportunities, and approach to realizing this ambitious goal. While a number of these conclusions derived directly from individual working groups as discussed in Part II, the primary conclusions were arrived at by joint consideration and cut across the groups. Even where a key observation was initiated by a specific working group, its real significance was only established when examined in the context of the other subdisciplines covered by the remaining working groups. This chapter briefly presents each of these major findings with discussion. Their implications for future work are presented in a following chapter.