iOS 5 Out Today
1) A tethered jailbreak is available via redsn0w for all devices except iPad 2 and the new iPhone 4s.
2) Tethered jailbreak means you will have to use redsn0w to enter DFU mode and have it “just boot tethered” every time you power cycle your device. (Just tapping power is fine, you have to actually shut it off).
3) After you run redsn0w, even the very first time, you will have a white cydia icon. This is because you have to still power cycle, enter DFU mode, and boot tethered. The next reboot will come after you install something that requires mobile substrate (almost everything). After installing this, the device will only hit apple logo unless you do the boot tethered option.
4) If iOS5 turns out to be stable, tethered jailbreak may be manageable for many of you. But be aware that if something happens while you’re away from your computer and your device restarts, you will have to get to a computer before you can use your device again. This is probably not so bad for an ipod or ipad. Maybe not great for your only phone.
5) Many free and paid tweaks have not yet been updated. Developers are working on updates so be patient.
6) Non-factory unlockers should stay away from ios5 for now or you will lose your unlock! (This should go without saying).
7) iOS 4.3.4 and 4.3.5 is also tethered, so 4.3.3 is the only firmware that can be jailbroken untethered for now.
8) Improperly written notification center add-ons may cause your device to be in a reboot cycle. A mobilesubstrate update is due out later this week that will protect you against this. To protect yourself in the meantime, make sure you have openSSH installed so you are able to manually delete any notification center tweaks you install should this happen to you. Otherwise, you will have to restore and jailbreak again.