Update: Also do not yet update to iOS5, especially the GM which will expire. For info about iOS5, go here.

Update: all this applies to 4.3.5 as well.

As I predicted 10 days ago, Apple released iOS v4.3.4 today. This does nothing except patch the jailbreakme.com jailbreak from comex and, in the process, patch i0nic’s exploit making it so we cannot jailbreak 4.3.4 untethered. Im not sure if Apple has stopped signing 4.3.3 yet so if you havent then load cydia or tiny umbrella and get your shsh saved off. Additional warning to iPad 2 users. If you have a 3G iPad, even saving the shsh won’t be enough to restore 4.3.3 because the baseband is also under shsh protection now. Wifi only iPad 2′s and all other devices are still protected by shsh storage.

Again, do not update to this firmware. When iTunes asks if you want to install the new firmware, say no. If you update then you will gain nothing and lose your jailbreak.

This warning goes for 4.2.9, which is the CDMA version of the patched firmware. Do not install that either.

And no, this update provides you no new features only closes the jailbreak.