As iOS 4.3 final version to be released next week,
iPhone iOS 4.3 jailbreak and unlock rumors to come too.
iOS 4.3 beta 3 untethered jailbreak to launch after iOS 4.2.1 jailbreak for iPhone 4, 3GS, 3G & iPad 2.

A member of iOS 4.2.1 untethered jailbreak and member of Chronic Dev Team has tweeted about iOS 4.3 jailbreak, he is tweet from Stefan Esser,
I heard @securetips will release a iOS 4.3 untether exploit after next weekend. Follow him for news.
The person who is an anonymous hacker was worked for Apple, he is unknown but as per Stefan. We dn not take the rumor very seriously and also suggest others to take it as grain of salt.
On other side, Apple will launch iPad 2 event on March 2, and
iOS 4.3 rumored to be released at the same time, also
iOS 4.3 Untethered jailbreak to be expected by more Apple users.
You may like:
Comex's JailbreakMe 3.0 for iOS 4.3 Untethered Jailbreak to Release Soon
RedSn0w 0.9.8 & GreenPoiso0n RC7 with UltraSn0w 2.2 to Release for iOS 4.3 Untethered Jailbreak
Latest Update Collection of RedSn0w 0.9.8, GreenPois0n RC5/6 for iOS 4.3 Untethered Jailbreak