It took less than 24 hours after being announced at Apple’s WWDC conference but it seems that no sooner had the developer’s beta of iOS5 been made available than it was jailbroken by an iPhone hacking group known as the Dev-Team.
According to a message on the Dev-Team’s @MuscleNerd’s Twitter stream he was able to jailbreak iOS5 running on an iPod Touch 4G using something called the limera1n jailbreaking method.
Unfortunately, this jailbreak is tethered, which means you have to have your iPhone/iPod Touch/iPad connected (or “tethered”) to your computer whenever you reboot your device, in order to maintain the jailbreak. Most jailbreakers will likely wait for an untethered option to become available before proceeding to upgrade to the new OS.
As proof of the jailbreaking @MuscleNerd posted the following screenshots.