Apple has started to release new iPhone 3GS handsets with an updated bootrom and we reported that it rendered those Eric McDonald, an iPhone Dev-Team member, said in a Wired interview released last week.. However, this isn't true,
MacDonald said, "It's not going to be impossible to jailbreak even if the exploit we used is gone."
The existing tools used for jailbreaking will work with the newly updated iPhone 3GS handsets. The only problem is that Apple has patched the "24kpwn" exploit used to jailbreak previous models. The result is that the 3GS can be jailbroken, but it will only boot after being turned off while tethered to a computer. What this means is that if you are away from your computer and your iPhone runs out of power, you will only be able to turn it back on by plugging it into your computer, not the included AC adapter. Worse still is that if your iPhone crashes and you need to reboot it, you had better have your computer handy. If you don't have one, your iPhone will become a handy paperweight until you do.
We suspect that these circumstances are the same for the current third-generation iPod Touch. However, the second-generation iPod Touch suffered the same fate and eventually the Dev-Team released a fix that lifted the tethering restrictions. We think that eventually a similar fix will be released for Apple's latest iPhone and iPod Touch.
The caveat of having to tether your iPhone 3GS (or iPod Touch) to turn it on or run the risk of it turning into a paperweight after a crash or reboot might not make jailbreaking the updated devices worthwhile for many people.