Uh, no. From a stat weight point of view, haste has high stat weight for Shadow Priests and Warlocks. Mages, otoh, rate Crit and Haste pretty equally. Since the staff is Hit/Haste, the stat weight says it would be far more beneficial in the hands of a Warlock or Shadow Priest cause they would get more out of the Hit/Haste than a Mage would.