Apple has released iOS 4.3.4 as a step to cover the pdf- exploit the JailbreakMe 3.0. So actually this is just security update 4.3.4 update only, no new features of the iOS 4.3.3 to 4.3.4.
For that, you should not need to update to 4.3.4 for the current iOS, or jailbreak the iPad 2 and other iDevice, you will be lost.
Quickly Dev Team finally released RedSn0w 0.9.8b3 as an answer to jailbreak iOS 4.3.4. Unfortunately, this jailbreak is tethered jailbreak, and it seems Dev Team and others did not plan to release a jailbreak for 4.3.4 untethered because it would be a waste of manpower and time, they should focus on the iOS 5.