Every ranged DPS and healer should download this addon, get it here:
http://wow.curse.com/downloads/details/9804/It has 2 features which helps you to avoid the orbs.
1) It announces to you that you have been targetted by orb.
2) If you are in range of an orb, your screen will turn to blue. This helps to avoid bombs that didn't target you but someone else near you. It will also show the direction of the bomb and distance in yards. Try it and be amazed.
It is not enough if you can move away from orb targetted to you, the orbs targetted to other players will still hurt and kill you. This addon helps especially with the latter part which is why you should get this even if you have DBM or Big Wings. If you don't understand what I am talking about, go ahead and download the addon anyway, you will see. So if you don't get this addon and keep dying to orbs, what's the point of trying to do any progress? I don't really want to keep wipeing on VR just because some people are so lazy that they don't get the addon. Takes only few minutes but saves many hours and repair bills.