Images have surfaced showing the recently-released American version of the Apple iPhone 4 unlocked, running iOS 4, and accessing Bell Canada. The feat was accomplished by MuscleNerd and PlanetBeing of the iPhone Dev Team, and required a complete rewrite of ultrasn0w software thanks to the new baseband OS in the iPhone 4. The duo said that previous versions of redsn0w wouldn't work on the new device.
Keep in mind that iPhone 4 devices eventually sold in the UK, France, and Canada will have an unlocked option--meaning the SIM-free phones can be used with any mobile carrier the user chooses. US-based residents--up until now--were forced to purchase and import the device if they didn't want to be locked down with AT&T.
As for the American versions, its believed that jailbreak and unlock tools won't be made available for the public until after the new firmware update--iOS 4.0.1 or v4.1 (whichever comes first) for the iPhone 4, iPhone 3GS and 3G. The latest development certainly brings hope and anticipation to the jailbreaking community--even Cydia has been seen up and running on the iPhone 4.