Apple have released the latest iPhone OS – iOS 5.0.1 to patch a security exploit and other features – if you have already jailbroken your iPhone do not upgrade to iOS 5.0.1 via iTunes.
If you want an untethered jailbreak in the future, you will need to wait until a redsn0w version is released that can create a custom IPSW for 5.0.1, the current version 0.9.9b8 does not make a custom 5.0.1 IPSW – it can only create a custom iOS 4.3.3 and 5.0.0 and preserve the baseband.
As well as fix a security issue the upgrade also improves battery life on some models and gets Siri up to speed on ocker Aussie accents!
If you have already jailbroke your iPhone and are on a iOS version lower than 5.0.0 then you are encouraged to upgrade to a custom iOS 5 before Apple stops signing that version of firmware. Apple has stopped signing the iOS 5 firmware making a jailbreak impossible – if tried you will get restore errors like ‘3194’ or device not eligible for the requested build – but there will be a jailbreak to 5.0.1 soon.
Looks like another Apple release to the iOS is more likely to happen very soon to iOS 5.0.2 as there is a lot of complaint about battery life, antenna and Wifi issues – if this is the case it is more than likely that a jailbreak exploit to the latest iOS will be delayed until iOS 5.0.2 is released.
These are the official Stock iOS IPSW files which will eventually be needed to make custom IPSWs when the jailbreak software is ready.