The PS3 client is available!
It is developed by SCEA R&D, Sony Computer Entertainment US Research and Development.
It is unsure if the PS3 Folding@home client uses the same update mechanism as the CPU, SMP and GPU clients.
The screenshots of the PS3 client report the core name as SCEARD2 at version 1.9.4885.
The Currently Running Projects lists the core as GRO-PS3.