It's not as though the PS3 hasn't been hacked before; it has. In fact, longtime iPhone hacker Geohot was involved in one of those. However, the release of the PS3 3.60 firmware closed those holes. Now, the new hack could blow things wide open. It's explained here.
... the reveal of the LV0 key basically means that any system update released by Sony going forward can be decrypted with little or no effort whatsoever. Options Sony has in battling this leak are limited - every PS3 out there needs to be able to decrypt any firmware download package in order for the console to be updated (a 2006 launch PS3 can still update directly to the latest software).What's interesting is that the key may never have been publicly released if someone hadn't tried to make some money off of it.
The release of the LV0 key allows for that to be achieved on PC, with the CoreOS and XMB files then re-encrypted using the existing 3.55 keys in order to be run on hacked consoles.
Indeed, the people who tried to make a buck off of the hack were not the original hackers who first uncovered the key. The information leaked and ended up being a profit center for a new Chinese hacking group who call themselves "BlueDiskCFW." That group planned to charge for and release new custom firmware updates.
The "Three Muskateers" released the key themselves in order to prevent "BlueDiskCFW" from making a profit from their work. A statement from the hackers said,
You can be sure that if it wouldn't have been for this leak, this key would never have seen the light of day, only the fear of our work being used by others to make money out of it has forced us to release this now.