The A* grade is just another example of the government and exam boards giving into grumpy idiots who moan every year in the mass media.
It'll only be achieved by maybe 5-10% of candidates, hence this will negatively impact 90-95% of candidates.
The A* grade is pathetic, shameful and will probably lead to increased stress by the majority who work very hard and don't get A grades at A-level.
Sorry for the rant-type post (I had the equivalent of 3 A*s in my AS results, as an FYI) although I can't stand it when idiots complain that exams are getting easier. They're stressful, they are not easy.