Stefan Essar is set to release his untethered jailbreak tool for the iOS 4.3 anytime next week. The tool was demonstrated in a YouTube video he shared earlier today. It showed the first generation iPad running the untethered jailbreak version based on an exploit that is yet to be disclosed. The procedure for installing this is similar to that of the previous versions of the iOS, meaning you will be needing bootrom exploit for installing the same in the root partition.
The version will not work on the iPad 2 since the public bootrom exploit is not yet available for the second generation of the iPad. Even the current release is not yet ready for the final release and would be needing some patches before the release goes public. Stefan also added more details in the release stating:
However I recommend the dev-team or chronic-dev to first release a *tethered* iOS 4.3 so that everyone can test if their nice feature actually work. I guess most people require Mobile Substrate to work and AFAIK it does not work due to ASLR. It would be a waste if Apple kills an untethered jailbreak before Mobile Substrate works.
That said I will release the jailbreak when a) there is no other untether by the time I am finished b) if MobileSubstrate works.
We will be updating the same as soon as we hear more on this.