People keep saying "there will be someone else". There doesn't have to be someone else. Finding exploits is hard and very time consuming. There has been much less talk about this jailbreak than any other before it. And most of the talk about it is how none of the main people who have done it in the past are working on it now. Seems pretty dead to me...
Pretty much this.
The fact that a jail break has been published is due to a SECURITY FLAW in iOS.
Apple will patch these as they are discovered - they would be negligent not to as jail breaks aren't the only things these could be used for - malicious software installs being another potential application (and as an aside, there's no reason someone couldn't combine a jailbreak with such software, turning all the machines jailbroken with that particular hack into their own personal botnet).
At some point, it is likely there will not be any security flaws that are exploitable to the extent of being able to circumvent the code-signing imposed by the OS.
Maybe this tipping point is iOS 6? Maybe it will be iOS 7. But the bar is certainly being raised with every new release. If nothing else, they will take longer to be released for each new iOS.