Lovely how people claim that this will get nerfed.
Why would it be, this is like almost the only way for engineerers to make gold these days.
I always combine this with the Nagrand quest for the Shattered Sun Offensive, best result i´ve come up with so far is like around 10 primal in just one hour, including lots and lots of adamantite ore/fel iron ore
So no, this WONT ever get nerfed.