From the research performed by several people so far, it's very likely that the "demo" versions of CherryOS have actually been modified versions of PearPC. There's fairly compelling evidence of this (so essentially he'd be charging $50 for the nice installer, wizard, and UI improvements).
If true, this probably means it's a hoax to the extent that: Claimed "80%" speeds are **extremely** unlikely, as even with major architectural improvements the PearPC team believes it will only improve to 10% efficiency, the "not using any PearPC code" claim by the author is false, that they'll be violating copyrights if they don't return source code to the community, etc.
I personally hope that the claims are true. I've seen too many of these kind of out-of-the-blue, too-good-to-be-true softwares to believe it (anyone remember the fractal compression stuff back in 1990 that was supposed to allow you to back up your 100MB hard disk to a 720KB floppy? And even seemed to work? Yeah, hoax =), though it's probably not an outright scam.
