Part of the allure of drums in raids has been the ability to overlap the effects of different types of drums by having several leatherworkers drumming at a time. One member might boost attack power and spell damage for party members in range, while another might restore health and mana.
With the new Tinnitus debuff, any targets affected by drums are immune to the effects of all other drums for two minutes. While this sounds like a nerf, it might actually have a balancing effect.
In fact, other professions are seeing similar changes. Potions will create Potion Sickness, which will prevent the consumer from using more than one in any given encounter. Players will have to rest out of combat in order to refresh the privilege.
So far, this also is affecting mana gems and similar items, although it is unclear if that particular effect is a bug or not. What does this mean?