and there is no PSP port of the jailbreak yet. It's already been ported to a god damn toaster along with 80 hojillion esoteric phones no one has ever heard of, yet there has only been a peep so far about the possibility of a PSP version.
I think it's more to do with the original exploit code being ported to something which the psp can understand - which isn't something as simple as a "google translate linux to lua"!
The original exploit (AFAIK) was designed for linux environments, and i believe that the psp uses lua/c. So the code would have to be ported from whatever it's native language is to lua or c to work on a psp.
However, i say this without having seen the exploit code and without having coded for the psp, so please correct if wrong!
i suppose this registry can be written via linux-jailbreak or with a nand flasher (like infectus) but sony can't fix this?
The nand is encrypted, so it would not be possible to just write one file using an infectus. And quite frankly, the infectus probably can't write to the nand on most ps3's because they updated the chip to a newer type and the infectus can only write data in one type of way. Chances are it wont happen, at least not with an infectus.
The guy who is writing a PSP port said he was going to write an emulator of the Teensy which seems to be a massively over complex way of executing some basically simple code (which is very timing dependant more than anything)..
A dedicated usb dongle seems a far more practical method.