UPDATE: Digital Foundry's Rich Leadbetter had this to say on the latest PS3 update:
"Yes, people have tried it and the Jailbreak no longer works.
"3.42 is the only way to access PSN, so in Sony's world you have to upgrade. However, for now it looks like people who have the Jailbreak are sticking to 3.41 and using a proxy server bypass to remain online.
"Going forward, the hackers will be attempting to reverse engineer future firmwares and producing custom versions that keep the exploit working."
ORIGINAL STORY: A new update for the PlayStation 3 released this morning may combat the PSJailbreak hack.
Version 3.42 is described as "minor" by director of hardware marketing John Koller, but "includes additional security features".
While Sony is yet to reveal the intention of the update, many speculate it combats the high-profile PS3 crack which exploded onto the internet in August.
Earlier this month an open source alternative to the PSJailbreak hack, called PSGroove, was released.
The open source version of the jailbreak is effectively a clone of the commercial hack, which has yet to make it in volume to the modchip suppliers.
The crack allows PS3 users to copy all the games they own - and any they don't - onto hard disk.