from the register :

MP3 Pro is sufficiently compatible with the existing MP3 - aka
MPEG 1 Audio Layer 3 - to allow MP3 decoders to play back files
encoded using the new technology, though they won't benefit from
the extra level of compression.

from consumer electronics :

Content encoded in mp3PRO can be played back in a traditional MP3 player but without the quality enhancement.


You're right, it seems impossible to get a quality improvement in output with the same sequence of zeros and ones as input.
Especially the first statement I think is very doubtful. How can it not benefit from compression when the same file is used on both decoders?
They're gonna launch it in 80 days or so; guess we will have to wait and see...

Frank van Gestel