I'm guessing it will be around 400-600Mhz, which should still be enough for AmigaOS.
It's probably based on
this, meaning it will be quite similar to your Efika (i.e. 400MHz). Genesi and THTF (a Chinese OEM development company) initiated a netbook project together some years ago based on this CPU (before their relationship crashed, and before it turned out that the CPU lacked HW cache coherency, and Genesi went ARM instead), LimePC, AFAIK this is still being sold in China and this is is AFAIK the only PPC based netbook ever built. You might also have seen it (or rather the "nettop" variant based on the same HW) resold as "Cherrypal" as well. It's a cheap, low watt CPU, and I'm not aware of any other CPU really suitable for netbook design. And "suitable" is a matter of definition, since besides lacking cache coherency, it also lacks several important features users would expect from a netbook, like HW accelerators for multimedia and video decoding/encoding...