I think it's pretty likely that at least some future Hi-MD units will have built-in MP3 decoders -- maybe encoders for recording. If Sony doesn't do it, someone else will license the Hi-MD technology and build in the decoder for playing MP3 files.
It should also be reasonably trivial to make a Hi-MD system look like an external hard disk to a USB-connected computer, so transferring existing MP3 files could become a drag-and-drop operation. Then the Hi-MD unit could sometimes be operated in a mode where it's essentially just a media player.
Jim
