huge milestone indeed but its so easy for them to stop this via new firmwares now, especially as you are forced to update it if using your machine online.
hope the usb thing comes like the memento hack on ps2 which used a ps2 memory card with mini usb on it so you could link it to pc and update the software.
Sony enabled linux on the ps3 from the start that's why there weren't many skilled hackers trying to break the security. I think this was an incredibly smart and insightful move from sony
The jailbreak software comes on a USB key, hopefully someone that buys it can throw it up on a torrent... pirate the jailbreak so we can pirate games on the ps3!