Yesterday was a big day for Apple at WWDC 2010, with Steve Jobs unveiling the iPhone 4 and also renaming iPhone OS 4.0 to iOS4. However, less than a day after iOS4 was made available to developers, there is already a jailbreak for iOS4 on iPhone 3GS.
The 3GS iOS4 bundle can be used to jailbreak devices running iOS4 GM on an iPhone 3GS. The bundle has been created by msft.guy who is also known for fixing the blacksn0w unlock for iPhone OS 3.1.3.
If you are a regular iPhone user, you might as well stay away from this as this is only for a GM release of the iOS4 and may not work on the final iOS4 version considering that Apple still has time to fix the loopholes in it. However, this just goes to show that a jailbreak for iOS4 will be available once it is released.
If you are an iPhone 3GS, iPhone 3G or iPod Touch users you will be eligible for a free upgrade to iOS4 on June 21st.
Not convinced yet? Check out a video of a jailbroken iPhone 3GS running iOS4 GM below.
You can download the file iPhone2,1_4.0_8A293_bundle.zip from this site.