OP - could you clarify what you're asking? I'm not sure what you're on about with this thread. I used greenpois0n to jailbreak mine when I updated to 4.1, everything is going smoothly, and I believe that is the case for many others that used one of these tools to jailbreak 4.1.
Is your question directed to all the recent talk of using redsn0w/pwngetool (sorry can't remember what's working as of this moment) for a tethered jailbreak, if so that's for people that want to go ahead and upgrade their firmware from 4.1 to 4.2.1 and re-jailbreak. Some clarification would be appreciated.