So what should iPhone jailbreakers and unlockers do?
MuscleNerd of the iPhone Dev Team has advised users who want to jailbreak and unlock their iPhone to avoid upgrading to iOS 4.0.1:
Obviously avoid today's 4.0.1 update until JB tools are updated.
However, the good news is that the baseband hasn’t changed in iOS 4.0.1 so Ultrasn0w 0.93 that should be able to software unlock your iPhone (once it is jailbroken).
MuscleNerd has also confirmed that Ultrasn0w will work:
Luckily, no baseband change so ultrasn0w lives on 🙂
Dev Team is also advising iPhone 4, iPhone 3GS and iPod Touch 3rd generation users to take a backup of iOS 4.0 SHSH blobs (ECID files). You can checkout our step-by-step guide on how to take a backup of SHSH blobs:
Luckily, iPhone 3G users and iPod Touch 2nd generation (non-MC version) can use Redsn0w (v0.9.5b5-5) to jailbreak iOS 4.0.1. If you need help, you can checkout our step-by-step guide on how to jailbreaking iOS 4.0.1 using Redsn0w:
Update:MuscleNerd, iPhone Dev]