PwnageTool bundle to jailbreak iOS 4.3 GM on iPad (Wifi+3G) has been released by DjayB6. This bundle and updated version of Ramdisk Fixer (v1.5.2) can be used to patch PwnageTool 4.2. You can create iOS 4.3 GM custom IPSW for iPad using the patched version of PwnageTool, which on restore through iTunes will jailbreak your iPad on iOS 4.3 GM.
As confirmed by DjayB6 himself, it will be a tethered jailbreak which means if your iPad looses power due to low battery or any other reason, you will have to use Tetheredboot Utility to boot into a jailbroken state on every restart.
The instructions to use iOS 4.3 GM PwnageTool bundle for iPad are exactly similar to usage of PwnageTool bundle for iPhone 4. Just download the bundle file from the link below and follow the step-by-step guide here for a tethered iOS 4.3 GM jailbreak on iPad.
Download iOS 4.3 GM PwnageTool bundle for iPad (Tethered Jailbreak)
Download iOS 4.3 GM PwnageTool bundle for iPad [Tethered] [Bundle by iH8sn0w] [Do not require Universal Ramdisk Fixer Patch] [Recommended] [Mirror]
Update#1: Download iOS 4.3 GM PwnageTool bundle for iPhone 3GS (Old Bootrom)
Update#2: Download iOS 4.3 GM PwnageTool bundle for iPhone 3GS (New Bootrom)
Update#3: iH8sn0w, the famous iPhone hacker behind Sn0wbreeze tool, has released his own PwnageTool bundle to jailbreak iOS 4.3 GM on iPad