I'm still playing WoW, albeit not with the same fervor as before. I spend a lot of time dancing on mailboxes and doing other stupid things, going out to fight only when Ed or somebody else is around to team up with.
In the process, I've begun to notice some of the problems that combat healing brings to game design, and have come to the conclusion that, if I ever design a large scale persistant multiplayer role playing game, it will not contain any combat healing at all.
Now, combat healing has been a staple of the genre since its inception, and it's become so engrained in how people play that it's difficult to imagine a game without it. However, if you can look past the "it's always been that way!" mindset and look at how it damages gameplay, you might just agree with me that it's time to get rid of it once and for all.
EQ is the anti-combat-healing poster child, so I'll poke at that first. This is a game that was built, from the ground up, with the "perfect group" in mind. EQ was warrior/priest/mage all the way, and for the longest time it suffered all the more by having so many classes with only one viable healer. With the game designed specifically around this group composition, most other groups were simply incapable of doing much of anything, and playability as a whole suffered greatly.
The net result of combat healing in any game is that you end up having one player who essentially sacrifices himself to make other players vastly more powerful. That creates 2 major problems right there - from the healer's perspective, it's a boring and thankless job, and from the designer's perspective it's a difficult dynamic that must be worked around.
In practice this leads to an unfortunate situation - one in which the game is, by necessity, designed around the potential groups with healers that are vastly more powerful than groups without. This means that, to keep content from becoming trivial to the "right" group, you must "design out" groups that are lacking healers, since an objective that's a challenge for a healer-equipped group would be downright impossible for a group with no healer.
The reason this is doubly bad is that, as I previously pointed out, healer is a thankless and unglamourous job, and one that most people want no part of. You sacrifice your own offensive ability to play backup to the superstars, the fighters and mages who are doing the fun work of engaging the enemy and making things dead.
That leads - you guessed it - to a healer deficit. Not enough people have the desire to play them, but they're needed for a lot of content.
Of course, some people enjoy playing the sidekick, but there will never be enough willing healers to provide every group with the perfect composition. The selfless among us, those who are willing to take one for the team, may set aside their preferred playstyles and create healers simply because healers are so essential. These poor souls suffer through the game just to make their groups viable, all the while wishing they were playing something else.
WoW, a game designed around having people solo a good chunk of the content, exascerbates the situation. Since (unlike EQ) you're expected to solo for most of your career, picking a dedicated healer means that you're simply less effective than most for a good chunk of gameplay. In a game with forced grouping, where almost nobody can solo effectively and you'll always be in a group no matter what you do in combat, healers are less painful - but in WoW, their offensive disadvantage is even more pronounced when they try to go it alone.
This can be somewhat mitigated by spreading out healing amongst severally equal viable alternative classes who all have other primary abilities; however, in the case of WoW, there is a single class that is simply superior to all of the "secondary" healers. Combat healing as a "class defining" ability creates the biggest issues - since healing is the single most powerful ability in party play, having a single class that is well above and beyond the rest of the healers means that:
1) The best (class defined) healing class will provide proportionally more power to a group when compared to his non-class-defined counterparts than any other class-defining role (e.g., the class defined healer will have abilities that vastly enhance the combat abilities and survivability of the group, whereas a class defined nuker or meatshield does not scale to such an extent).
2) You must balance the "difficult" parts of the game against groups that will have the class defined healer, which makes secondary healers undesirable in groups facing the difficult content.
3) Given the class defined healer's disproportional benefit to groups, his other abilities (damage dealing, etc) must by necessity suffer, or else you create a superman out of an already overpowered class.
All of this indicates that combat healing itself is the biggest barrier to balance in MMORPGs, and should be one of the biggest thorns in the side of players and developers alike. It forces specific group composition for maximum effectiveness, it forces design decisions to be based around that group, and it imposes a "correct" playstyle that simply must be worked around.
However, there are some possible solutions:
1) Use the potion-like cooldown for targets of healing, wherein each person can only be healed once in the course of a normal-length battle.
2) Remove the class defined healer and have several equally viable healing classes that have non-healing primary abilities.
3) Have only long cooldown times on healing spells, to prevent "spamming" heals which makes melee characters and pets virtually invulnerable.
4) Remove combat healing entirely, leaving only specialized very-high-cooldown abilities such as Lay on Hands that have value in being used sparingly, only to recover from dire situations.
The benefits of eliminating combat healing entirely are immediately evident:
1) You don't have to balance around a high-powered healer, thus enabling a wider variety of viable group compositions
2) You prevent the creation of an offensive gimp just to satisfy the need for a dedicated healer.
3) Combat will be faster since encounters will be designed without having characters with virtually infinite hitpoints.
The downside... well, the downside is that you take away healing from people who enjoy having it. A small price to pay, I think, to fix a broken game dynamic.