One of the neat things about this is the utility. For instance, let's say you're a guardian druid and the only combat rez in a 10 man. You give Rebirth to a Holy Paladin, which is nice since they can cast it and you don't have to worry about a clutch rebirth while tanking.
You wipe, and you just happen to have a second holy paladin in the group. Could you change the symbiosis to that paladin and reset a combat rez cooldown?
Obviously can't test this yet, but something to look at when we can. Since you could probably drop combat fairly often in RBGs, it'd be interesting to see how this works. I could see this also being abused with tranquility and disc priests in a 25man, between wipes.