The Mecca’s power-sharing agreement with Fatah-PLO is a victory for Hamas. The government was unified on the Hamas’ terms: no recognition of Israel, the rights of Palestinians (implicitly to the entire Palestine, including Israel), the return of millions of descendants of 1948 refugees to Israel, and the like pronouncements which long set out teeth on edge. The agreement sort of legalizes Hamas as senior political partner of “moderate,” internationally accepted Fatah. Before the agreement, Hamas was an outcast, and feared new elections: pragmatic Palestinians might not have voted again for troublesome Hamas. Now Hamas is the same as Fatah, but better: politically respectable government party, welcomed in Mecca, ready for inter-Arab dialogue, bringing money in, but, unlike Fatah, consistently anti-Israeli. Abbas’ voters have every reason to flock to Hamas.
Saudi king pushed the Hamas-Fatah agreement through where Egypt and Jordan failed. That says a lot about Saudi influence of Hamas. American ally finances the terrorists who aim at destruction another American ally. Roman Empire did not allow such subversion. 
The much-touted point of the agreement, Fatah’ regaining control over the Interior Ministry, is nonsense. The government troops were loyal to Abbas, anyway. Hamas ceded the ministry which it could not control. Overall, the government remained in Hamas’ hands with only symbolic curtsy to Fatah.