Just a day after Apple released the iOS 4.3 beta to developers, an unofficial version of PwnageTool that can jailbreak the new OS is released. The new PwnageTool is based on the Limera1n exploit that has been around for a while now.
WARNING NOTE: (Advanced Users Only) This unofficial version of PwnageTool (with custom bundles) wont preserve your old baseband. If you rely on an unlock, stay away from this release. Proceed at your own risk only. We are not to be held responsible if you end up bricking your iPhone.
Follow the instructions below to jailbreak iPhone 4 on iOS 4.3 beta using PwnageTool here.