Xenons as standard mean fogs are pretty useless.
Had them on cars for years and never really had a use for them. lets face it they are mainly used incorrectly and add little to driving in the fog. I once had a calibra where they were in the main headlight cluster - pointless.
Having said that have you noticed the Audi R8 running lights series of bright LED's (saw them on an A8 too).
Prepare to see the same happen to factory fit headlight units as the maxpower brigade have done too rear clusters......