MuscleNerd tweets that iOS 5 beta 3 can indeed jailbreak iOS 5 beta 3
However…there is currently a sandboxing issue in iOS 5 beta 3 that will cause ALL App Store apps to fail to launch. So you might want to hold off on jailbreaking and leave that to the devs. No word on if there will be a fix for this anytime soon.
The rest of this post was originally from an earlier posting.
The Dev Team has jailbroken iOS 5 just 3 days after Apple released it to developers following WWDC.
Props to the Dev-Team once again for releasing a jailbreak very quickly for the new beta. Keep in mind this is a tethered jailbreak with redsn0w, meaning you will need to connect your device via USB to have it boot jailbroken. Once this is done you can disconnect and remain jailbroken until you reboot the device.
Full details available at the Dev-Team Blog: