Prominent iPhone hacker i0n1c revealed in a tweet yesterday that the untethered jailbreak he created has been fixed in iOS 5.
R.I.P. – I just heard Apple killed the ndrv_setspec() integeroverflow and his friends in iOS 5.0b1 – if this is true the untether is dead
It was discovered yesterday that the tethered jailbreak in limera1n worked perfectly in iOS 5 with Cydia running smoothly, but for those hoping the untether from i0n1c would work, it looks like those dreams have been put to rest.
This doesn't mean another untethered jailbreak won't be discovered, although the jailbreak community most likely wouldn't release it until the iPhone 5 is available to prevent Apple from finding the exploit and patching it at the hardware level.
Would you be open to using a tethered jailbreak with iOS 5 or would you stick with iOS 4 until an untethered jailbreak is available?