iOS5 jailbroken on ipt4g: http://is.gd/7GxIcK http://is.gd/BwPvfh via limera1n + tethered boot..not too many surprises
Cydia works fine too from quick testing (I installed SSH) http://is.gd/oADWEo
It is currently tethered, that means jailbreak is gone after reboot. Hopefully i0n1c will be able to port his untether to iOS 5. Anyway great news for all jailbreakers!