Based on what is written on this forum:

1) Speed run are a must, so the tanks have to make mega pull (maybe all the dungeon);
2) The healers have to heal, but they also have to dps, because many pro on this forum said pro healer (like them) can clear dungeon with cleric stance always up (I read it just yesterday);
3) The healers also have to pay attention to the mechanics, otherwise they're lazy (I think it was on the healer's forum).

Gealers have to dps? No, but with a good tank and normal pulls (very rare conditions) they can contribute to the dps (and is even funny). Still, the current meta is one of worst I've ever seen in a mmorpg, with many tanks who want pull the whole dungeon (even if they have strengh gear and don't know how to use cd), and many dps who can't make decent damage and ignore the mechanics.

So I wonder, is it really a problem the lack of healer's dps?