What's best for Apple, musicians and music fans is if the labels don't exist at all.
The dynamic would work much the same way that it works now - except that musicians and Apple would take home more cash.
Apple are already involved in the production, manufacture, distribution and promotion of music. That makes them a record label, no matter what Justice Mann said.
They can't skip the intermediary labels and sign the musicians just yet, because most of their sales are coming from a back catalog that still controlled under the old paradigm - so if Apple starts signing bands, then their available catalog disappears.
So Apple is waiting for a quiet revolution, which the music industry could probably help along by creating the vehicles that will help artists get on to iTunes while they still own the digital distribution rights to their songs.