A new version of TinyUmbrella, the tool that allows you to take backups of SHSH blobs (ECID SHSH) has just been released to include support for iOS 4.3.4.
Apple released iOS 4.3.4 and iOS 4.2.9 on Friday to fix the JailbreakMe 3.0 vulnerability and the untethered jailbreak used in tools like Redsn0w, PwnageTool and Sn0wbreeze for iOS 4.3.1, iOS 4.3.2 and iOS 4.3.3.