Apple has adressed the hole in PDF viewer, and an update has been released for the following devices:
- iPhone 3GS
- iPhone 4 (GSM)
- iPod Touch 3gen
- iPod Touch 4gen
- iPad
- iPad 2
There are no other changes in the patch description.
It is also already possible to jailbreak iOS 4.3.4 using Pwnage Tool. Details are available here.