Topic Dark Sim in MoP
PvE utility of this spell is very limited. I've only used it on hagara so far. But I understand that it is very important in PvP.
Maybe they can add a Glyph that allows us to cast it on friendly players (instead of hostile targets) and it would give us the ability a (feral or guardian, depending on your spec) Druid would get if he/she used Symbiosis on that class.