We need to remember two things here though :
Firstly, Apple have released this version of iPhone OS 4.0 way ahead of any official launch of the new mobile OS. So they are unlikely to show their hand with any new protection measures, and give hackers advance time to try and work on exploits ready for the official release.
Secondly, the jailbreakers are aware that if they show their hand by making this hack public Apple will certainly plug it before any new release. That is assuming they (Apple) are not already aware of the exploit being used, and don’t plan to plug it anyway.
So don’t expect this to become a publicly available jailbreak solution any time soon. The game of cat & mouse between Apple and Jailbreakers continues. Right now it’s a kind of stalemate.
Let us know your views on these “naughty” hackers, and “oppressive” Apple in the comments.