All healers need tanks to live through focus fire and stop group damage. Commandos/Mercs just have it better in survival because in between taunts and guard you can pop your shell and stay alive, but they still die just like sages/sorcs. Sages really only have grip and a ranged interupt that makes them viable. I guess they can react to damage better with force armor then a merc can, but not having the reduced casting time on their big heal is going to suck ***. Who knows, with the increase in expertise (healers benefit the most from it) it might keep sages around the same. Thats more of a blind hope.
The game just sucks as a healer, because you rely even more on your teammates to live than in wow. I love it how some keyboard turning, tunnelvisioning mongoloid who can't even set up their smash right and doesn't interupt (or interupts the tail end of a healing trance lol) can basically force you to only heal yourself and even if you dead zone kite their charge, it won't be long till another bad gets on you and you die.