I hope that Iran turns into a secular democratic country, but the more realistic outcome would be a similar structure to the current one, but with less religious influence and more democracy. Or it could go the other way and become more autocratic and repressive. Though there may have been much support from protesters, the army, revolutionary guards, police and basij seem to have stayed loyal to the regime, so the opposition doesn't have much of a chance if that doesn't change.

At least the president now seems to be in dispute with the Supreme leader, as that will make it difficult for him to do much, and the opposition may be able to exploit that.

The UK shouldn't be too eager to say much, given past history, and other countries should also be cautious when commenting on the situation. Nothing better to rally support than to have evil outsiders meddling in domestic affairs.