Those looking forward to an untethered jailbreak solution on the iPhone 4S should heed the words of developer pod2g, who warns that the iOS 5.0.1 update should be avoided for now. The reason is because security exploits found in iOS 5 have been closed by Apple in iOS 5.0.1. These security flaws, publicized by security expert Charlie Miller, will simplify the untethered jailbreak process on the iPhone 4S.
If you're concerned about the security flaws, there are no reports of any malicious software actually using these exploits to do harm. Regardless, after the iPhone 4S is fully jailbroken developers will patch iOS 5 on their own with updates available through the Cydia jailbreak app store. The point is that if you plan to jailbreak your iPhone 4S untethered in the near future, the iOS 5.0.1 update should be avoided until further information is available.