iOS 4.3.4 released. Do not update your device if you're jailbroken.
This update was released to fix JailbreakMe 3.0 PDF exploit by comex. iOS 4.3.4 is for all iDevices - iPhone, iPod, and iPad (1 - 2). For Verizon's iPhones 4.2.9 was released.
Backup your SHSH blobs now.