For a few days in Cydia, the saved SHSHs for iOS 4.3 beta 1 are starting to be displayed. saurik started saving these SHSHs some time ago because this beta version of iOS 4.3 could be exploited with untethered jailbreak solutions on which the Dev Team has. The Dev Team used SHSH for iOS 4.2 beta in the idea of releasing an untethered jailbreak solution for iOS 4.2.1 but unfortunately gave up the idea because many people had to hack that version of iOS to jailbreak and others did not have SHSH. Cydia has saved SHSHs for iOS 4.3 beta 1 but is only showing them now because the whole process needs a few weeks to show the available SHSHs.
I don't think the Dev Team will release a jailbreak solution that requires the use of any beta version of iOS 4.3 to jailbreak, but it remains to be seen how things will be after iOS 4.3 will be officially available through iTunes.
