Have you played a healer in other MMOs? What aspects of the healing profession you found particularly interesting and would like to see them in TESO?

The following is my perspective: Pro-Active vs Re-Active Skills

Support is an essential element of a balanced team. So far, we heard about healing only. Although healing is needed, it is not particularly interesting. Bad support players tend to only watch the health bars of their team and fill them as needed. In contrast, good defensive damage mitigation requires a very different, pro-active approach. You have to constantly watch and assess the situation, predicting the incoming damage and applying short-lasting protection to the team members that need it the most. Thus, the focus is on the battle, not on the interface, and on prevention, rather that treatment.

Note that the emphasis here is on the defensive team-focused support. We can certainly snare or disable a foe as a form of damage mitigation or just plain slay it, and each player has its own block ability, but these aspects belong to the offensive foe-focused support (control) and offense, respectively. In contrast to the offensive foe-focused support, a large portion of players is interested in defensive team-focused support with typical classes such as clerics, monks, priests, etc. A term "healer" is somewhat unfortunate because it encompasses only a small portion of activity of such players. An effective defensive team-focused support player will certainly apply individual or group healing, but other aspects such as condition removal and protection, among others, play an essential role. In particular, the presence of pre-emptive, protection-focused anolytical gameplay, rather than simple healing, makes a defensive support-focused characters especially fascinating to play.

Let us consider a few examples. These spells are from Guild Wars 1.

Reversal of Fortune. Cost: 5 Energy, Casting Time: 0.25 second, Cooldown: 2 seconds
Enchantment Spell. For 8 seconds, the next time target ally would take damage or life steal, that ally gains that amount of Health instead, maximum 15...67...80.

Shield of Absorption. Cost: 5 Energy, Casting Time: 1 second, Cooldown: 10 seconds
Enchantment Spell. For 3...6...7 seconds, damage received by target ally is reduced by 5 each time that ally is hit while under the effects of this enchantment.

Aegis. Cost: 10 Energy, Casting Time: 2 second, Cooldown: 30 seconds
Enchantment Spell. For 5...10...11 seconds, all party members within earshot have a 50% chance to block attacks.

I hope that such protection-focused spells that aim to shield the teammates before impact to reduce the damage when it happens will be present in TESO. This will diversify the gameplay and make support-focused characters more exciting to play.

My favorite healer was the disc priest in WoW..but it was a terrible play style at the time..so I went to paladin and loved that way as well..especially the cone heal

Edit: also liked bards from almost every game..in Rift I tried pure support and it was tons of fun..I hope there is a viable support playstyle

I love wards / damage absorption, Rift's Purifier was good fun, nothing like completing a run and everyone realising they had taken no damage at all In EQ2 i loved Defiler/Shaman for same reason!

As for support I still would love to be able to roll a character that plays like EQ1 enchanter, No heals necessary but a mana battery with wicked Mez abilities & buffs... you dont need heals when the Mobs are controlled to perfection