I found the water/knock back rather effective as a solo Whm in Alpha. Was great for getting distance if my face was getting pounded and I needed to run and also for getting an otherwise interrupted spell off like Cure or a potion or even just to rebuff something real quick.

As for the idea of placing it in Tank/DD range, I never really thought about it but since it has been brought up I thought of this. As mentioned by V3rdict above, having to run around a camp to lose aggro was more of a death sentence then anything else as a Mage. With this I can push the mob back, allow the Tank to possibly be in Aggro range and "possibly" save me. If anything, it might reduce my chances of taking a massive melee straight to the face and be hit with a weaker ranged effect. i think as testing continues with CB1, more ideas of how to implement this new feature will allow for more tactical battles then just hope and pray hack and slash that V3rdict ALSO mentioned I would have to agree.