On a thread
at amigaworld.net a photo
was found which shows a small picture of a the PPC-motherboard called "Samantha" which will be introduced at the Italian Pianeta Amiga (23. and 24. September, Empoli).
The left part of the picture shows a platine without chips.
This could become a PPC440 which is a SoC- (system on a Chip) CPU available with up to 667 Mhz.