Few hours ago Apple has released the 4th beta of its new iOS 5 which was announced in June at WWDC and few hours after the release of this beta, Dev-team has updated their Jailbreak tool Redsn0w 0.9.8 to beta 4 to jailbreak iOS 5 on iPhone, iPod touch and iPad. But this jailbreak is tethered means you have to connect your device every time it is restarted to start it in jailbroken state, as there is no untethered Jailbreak in near future according to the Dev Team member.
The interesting thing about the iOS 5 b4 release is that it is an over the air update and more interesting thing is that the devices which have jailbroken iOS 5 beta3 will not be updated to beta 4 automatically. This means your jailbreak is safe till the time you update your device using standard iTunes method to iOS 5 beta 4.
Below is how iPhone Dev-Team member @MuscleNerd explained:
"The 5.0b4 OTA update won’t work on JB devices due to an explicit check of /Applications..almost like a present from Apple
NOTE: It appears that by design, the OTA update that became available starting with iOS 5 beta4 will *not* be automatically applied to jailbroken devices. That’s a relief to those who don’t want to lose their jailbreak via OTA pushes. If you’re jailbroken, you’ll need to use the standard iTunes method to get to iOS 5 beta4."
Remember that this version of Redsn0w 0.9.8 beta 4 will not jailbreak your iPad 2. Ipad 2 jailbreak is only available to the version 4.3.3 through @Comex PDF exploit but it is fixed in the iOS 4.3.4 update.
Redsn0w 0.9.8b4 is available for both Windows and Mac, you can download it from the Dev-Team official blog. Happy Jailbreaking!