Tonga's king has announced that he will surrender most of his powers, and in future act on advice from the Prime Minister. It's a good step forward towards UK-style constitutional monarchy, but it needs to be backed up with solid democratic reform, and soon. Otherwise, it will simply be a sham, with the king acting on the "advice" of unelected people he has himself appointed. But fortunately, there's progress on that front too, with the Tongan Parliament finally passing a Constitution and Electoral Commission Bill creating a commission to investigate reform and call a constitutional convention if necessary.
Will this be enough? We'll have to wait and see. But the spectre of the 2006 riots should be in the Tongan aristocracy's minds. If they don't offer a credible peaceful path to full democracy, then the Tongan people may create one for themselves, with far more bloodshed.