I actually plan to play my sorc as a main healer type class. If you compare the heal skill trees to the operatives which is really the only other suitable option, the end heals they get from the tree are MUCH MUCH better than the operatives. That being said I prefer the sorc for this because they have a more direct heal play style with a barrier cc and some dot heals to supplement the direct heals.
I plan to spec 31 corruption 10 lightning, from what I played in beta it didn't seem that there would be multiple class sets like rift, you can make variations of the classes because of the skill trees but I don't think you can load a different spec. That would mean to me no one should be asking you to heal a lot if you are specced to be dps, just lfg and what not as dps =)