Posted yesterday by Moorgard in the official Sony forums:

"Yes, it turns out there is a code issue that causes hate to be
assigned to the recipient of the ward/reactive heal rather than
the caster. In other words, it's not that druid heals are bugged;
they are, in fact, the only heals (aside from instant-resolve
ones) assigning their hate correctly.

Wards and reactives do generate hate on their initial cast, just
not over subsequent heals like they were meant to.

Now, this revelation probably causes some shamans and clerics
concern, because they see us fixing this issue and the result
being that they get pounded on. After talking to designers about
it, we realize that a huge change to healing aggro probably isn't
needed, just a more equitable middle ground.

We're going to evaluate the way hate is generated and will likely
make it so that wards and reactives generate somewhat more hate
than they currently do, and probably make regens generate somewhat
less. We don't want any type of healer to be shunned because they
draw more aggro when healing for the same amount of health. We'll
also take a look at taunt skills to make sure they're behaving as
we intend them to.

Keep in mind that healing, like nuking, shouldn't be done with
impunity. A healer needs to play with strategy, just as much as
any other class. The priest who pounds the heal keys without
thinking about it will take a beating, just like the careless mage
or the thoughtless scout or the witless fighter. Because as sure
as the sun came up this morning, at the first hint of a healing
aggro change in the update notes there will be countless "SOE made
healing useless!" threads, despite the fact that skilled players
will continue to play their priest classes just fine."

http://eqiiforums.station.sony.com/eq2/board/message?board.id=spellart&message.i
d=28528#M28528