Earlier today MuscleNerd confirmed that iOS 5 beta 2 can be JailBroken using the previously released Redsn0w 0.9.8 b1. As the tool is based on the limera1n exploit, so it is almost impossible for Apple to close it anytime soon. However, the untethered JailBreak could be an issue in the coming months. Someone in the hacking community need to find a solution for it till iOS 5 comes out of beta.
If you want to JailBreak iOS 5 beta 2 (only for developers) then simply point out the iOS 5 beta 1 firmware in Redsn0w 0.9.8b1 and follow the instructions carefully. You will definitely be able to tethered JailBreak your iDevice, that is, every time you re-boot the device, you need to use the software again for the normal boot. It is expected that @p0sixninja will release the iPad 2 JailBreak in MyGreatFest 2011.
iOS beta 2 is meant for developers. So, it is requested not to update if you are not one of them. Those who are using the iOS 5 beta 1 through any kind of hack should reverse back to iOS 4.3.3 because the first developer version will reportedly expire in August (particular date is not known). You can do it after saving the SHSH Blobs.