Strong, interesting multi-player is the reason why I think buff-centric characters need to be destroyed with fire. First off, buffs are boring as shit because it's typically a no-brainer decision when to use one. They often don't even have any true opportunity cost involved because there's nearly always a way to squeeze them out preemptively. Rarely does a buff change things to the extent that other players act appreciably different than they would had they not received the buff, leading to the curious situation in which the most group-centric abilities are curiously non-interactive. At least a sorceress laying down fire support might change who you target; a paladin's aura typically just means that you continue hitting things right in the face, only now you do it harder. Healing is also problematic in Diablo since if tradition holds than each character class must be reasonably self-sufficient through consumables when played well. Assuming that this is still the case, I would expect there to be a lot of over-healing involved with a true healer, since nobody with a brain in their heads really would want to leave their health total solely in someone else's hands when potions are an economical option. Healing would likely be reduced to the role it held in Diablo 1: post-battle patch jobs; convenient, but not something you can really balance a class around. Damage absorption abilities like WoW's Power Word: Shield would probably be more appropriate from a user friendliness standpoint, since the target could monitor the status of the defenses on his own to an extent, but those types of abilities run into all the same gameplay issues that a buff does; unless there's a real opportunity cost in the form of hefty mana consumption, debuff or a channeling requirement, such abilities are often simply too easy to use. I think there's a good reason that most of the "defensive" abilities we've seen so far in the trailers have been either crowd control related like Horrify and Mass Confusion or provide a zone of protection like Slow Time and Impenetrable Defense (provided you can keep the Monk between you and the casters, anyway). Such abilities are more interactive because they either cause opponents to behave differently or require your allies to be on the ball if they wish to benefit from your abilities. They also require some targeting or at least smart positioning to use well. Give me that kind of stuff over a fire-and-forget buff any day.