Jailbreak iOS 4.3.4 With RedSn0w

The Dev Team has released an update to the jailbreak tool, RedSn0w,
with support for a tethered jailbreak on iOS 4.3.4. Apple released 4.3.4 yesterday to combat the PDF vulnerability uncovered in the latest version of JailbreakMe.
JailbreakMe users are advised to stay with the untethered jailbreak that the web-based tool provides on iOS 4.3.3, and not upgrade to 4.3.4.

RedSn0w 0.9.8 beta 3: Mac – Windows

“For the convenience of kernel hackers like @comex and @i0n1c, we have a new redsn0w 0.9.8b3 that supports a TETHERED jailbreak for iOS 4.3.4 on all devices that have 4.3.4 except the iPad2.  The vast majority of people will want to stay back at 4.3.3 because that’s where the untethered jailbreak is! There are no new features in 4.3.4 — only fixes for jailbreak exploits.
Also, this is a good time to remind everyone (since we’re still seeing confusion about this): iPad2 owners with a baseband (3G or CDMA) cannot currently use saved blobs to go back to 4.3.3 once the signing window is closed. This is unlike every other device, so don’t be confused!  iPad2 owners with basebands should stay away from all updates to maintain the jailbreak!”

You can’t jailbreak the iPad 2 on iOS 4.3.4 with RedSn0w, so stay on 4.3.3 with your JailbreakMe untethered jailbreak. Because 4.3.4 was only released by Apple to combat the jailbreak exploit used by JailbreakMe in 4.3.3, there’s absolutely no reason for jailbreakers on 4.3.3 to update.
Apple is still currently signing 4.3.3, so make sure you backup you SHSH blobs immediately in the event that you accidentally update or need to downgrade back to a jailbreak-compatible iOS firmware.
The untethered jailbreak through JailbreakMe is the advised jailbreaking method for users on 4.3.3. To remain secure from the PDF exploit in iOS 4.3.3, install PDF Patcher 2 in Cydia once you jailbreak with JailbreakMe.