However, now I have seen two episodes and I feel that this version does have something new to offer. My son - who knows 0 about Jane Austen - sat with me and watched part of the first episode. After a while he remarked 'So basically, this is story about someone who is really unpleasant and wrong about everything?' And he's spot on. Didn't Austen say Emma was 'a heroine whom no one but myself will much like'? My son also said 'I wish there had been a revolution in England in the early 19th century, because people like that would have been shot.' And this version indeed makes the class politics more explicit than other adaptations I have seen. Knightly's goodness is linked to his stepping outside of the rigidities of class more readily than any other character.
I think this version makes Emma more outrageously wrong and youthfully cruel and ignorant than other versions I have seen, and rightly so, I think that is what the story requires for full impact. And it does this without (whatever my son thinks) making her completely unsympathetic and unlikeable.
Knightly, incidentally is played by Johnny Lee Miller and I was all 'What? He's too young!' but he isn't that young any more and I think he does a jolly good job.