It's been only a few days that the untethered jailbreak for iOS 4.3.1 came out, thanks to i0n1c's jailbreak exploit for the iPhone 3GS (Old and New Bootrom), iPhone 4, iPod Touch 3G, 4G and the iPad. As of now, there have been reports of an Apple iOS update namely iOS 4.3.2, that will fix i0n1c's exploit for the untethered jailbreak. The news is still a rumor, as only BGR has confirmed from it's own source. We'd keep you updated on this. In case the update comes out, DO NOT UPDATE if you are going to jailbreak your iDevice as well as software unlock your iPhone.
For those who want to have the untethered jailbreak their iDevices on iOS 4.3.1, kindly check our guide here.