In less then 24 hours after release of the iPhone OS 4.0 Developer Preview, iPhone Dev Team member MuscleNerd has successfully jail-broken the operating-system and installed Veency VNC application on the iDevice.

MuscleNerd also posted a video showing the jailbroken iPhone OS 4.0 running Veency (A Cydia hosted app), you can checkout the video as posted ahead. There is no expected time-frame for a public release but things look very much on track and an proper iPhone OS 4.0 Jailbreak seems eminent in future.