Pod2g has been keeping us updated on the untethered jailbreak status for 5.1 on the iPhone 4 and now the iPad 3. It seems he has finally finished his development and just updated saying his exploit works with 5.1.1 as well.
While there is no current ETA of a tool to be released for general consumers, he says he is weeks away from releasing a tool and not even $1,000,000 will make it happen quicker.