Can anyone on the PTR test whether mobs treat them as hostile and will actually attack them? I'm a bit concerned that it may become impossible to set up the portals without aggro'ing nearby bosses and mobs. Also do they have any AOE damage reduction? It would be horrible if a raid boss could just wipe them out with one of their abilities.
I'm also concerned that this change might severely damage their usefullness in battlegrounds. Surely they'll be destroyed very quickly, as soon as an enemy player notices them, and given they have 50% of the Warlock's HP they wont last long either.