I think a simple principle can be applied here:
What The Illuminati Want
1. One world government
2. One world currency
3. One world army
4. Population microchipped
5. No individual rights
6. People dumbed down to animal levels
They are all linked. At the moment a major obstacle to the microchip issue must be the lack of a world currency, considering that the chips are supposed to replace cash. If we have a single world currency that obstacle is removed.
Basically, if the Illuminati want it, it will NOT be good for us. Simple as that. So no, I think one world currency is a terrible idea because it will be an incredibly powerful system of control.