umm, why?
QFX uses low bandwidth, so its available to all 6m online users today - but on 23k use it. Unlike say RMA which requires fast downloads, QFX doesnt.
On the direct DES side, I dont see how this really helps, as music dowloads arent that "heavy" - in any case, its the fact that they are so light that makes piracy so easy (forgeting DRM etc)