As noted by Slash Gear, iOS jailbreak specialist MuscleNerd has apparently already jailbroken the new iPad that launched today, Tweeting a couple of screenshots showing the jailbroken device with Cydia installed.
MuscleNerd notes that this is simply the first step in the process of releasing a public tool for jailbreaking the new device, but it seems that progress should come relatively rapidly.
Article Link: Third-Generation iPad Jailbroken on Launch Day