A debug firmware update v3.66 for Playstation 3 has been leaked online by a hacker named "Consoledev". However there is no need to panic, as this debug firmware update works only with Dev Unit, and not with the retail PS3 units.
"No, this does not mean CFW, but this hopefully can be useful to devs in establishing the future of CFW. This firmware is only for developers, researchers and this will only work on TEST units"
User running this debug firmware update on a retail PS3 will get an error before the installation is complete, "The data type is not supported. (8002F029)".