A very great news for all the iDevice owners (Iphone 3G, 3GS, $), iPad, iTouch devices.
SHAtter is expected the name of the exploit found by for jailbreaking iOS 4.1. Shatter is also rumored to be tethered (you need to connect to computer after every reboot 
– still a speculation ) Jailbreak which jailbreaks all existing iOS idevices forever including iPhone 4 and iPod Touch 4G. Shatter will be a low-level bootrom exploit which will allow the use of unsigned code execution in order to jailbreak all iDevices for life even the iPhone 4 and the latest iPod Touch 4G. This is not publicly available though, but the iPhone Dev Team and the Chronic Team is working hard to release the exploits.
So sit tight, something is coming out soon.