Well, after my ps3 yloded (for the 3rd time) I decided to shove a ps3 disk into my laptop's drive. Turns out, it can read the disk, and I can see the USR_DIR etc. Unfortunately, the all files (not just the SELF etc.) inside USR_DIR are encrypted, just as you'd expect.
Is there any known method of decrypting the file layer with all the keys that have come out recently, or is it different for each disk?