Open Cl, end of manufacturers anonymity

Maybe someone can help with this.?? As I understand it, Open Cl is going to allow for a dispersed usage of both cpu and gpu, depending on app. OK, if thats right, then each component will have its own qualified Open Cl drivers, cpu and gpu.
Having diversity between drivers of each component, will this cause conflicts down the road by mixing and matching, IE using a Intel cpu with a nVidia gpu, and will having a full platform, like an ATI card using an AMD cpu together, or down the road, a Intel cpu with LRB, will it perform better?
But as they toggle from 1 to the other, depending on requirements, wont that in itself be an issue? Whereas, theoretically, having a "platform" driver set, itll be smoother? With better results?