I think that the BBC Edmund did a good job, he pulled of the character well, but he was the best of the BBC versions of the Pevensie's. The 4 in the newer movies pulled off their characters FANTASTICALLY!
First, the BBC Lucy vs. Georgie Henley. BBC: She was too winey, she did not look at all like the Lucy Pevensie I always imagined. She ruined Lucy's character for me, before the new Narnia movies came out. I had always hated Lucy because I really didn't like her character in the BBC movies. Georgie on the other hand... Well, thats a whole different story. She did such a good job, her character was not winey at all, she's very pretty, and over all, she was a good Lucy.
Now, BBC Edmund vs. Skandar Keynes. Honestly, they both did a good job. The BBC version pulled off his character very well, very obnoxious and little-brother like, always teasing and so forth and then later changed. The one thing that really bothered me was that in The BBC Prince Caspian, when Lucy sees Aslan the first time, he DOES NOT STAND UP FOR HER!!! He does this in the book and the new movie, but not the BBC version. That was very disapointing for me. Skandar also did a very good job pulling off his character, being the obnoxious traitor, but then turning around COMPLETELY!! He really pulled it off well I think.
Next, BBC Susan vs. Anna Popplewell. The BBC Susan was good as Susan, but could have done a lot better. Anna did a good job portraying the character and seems to fit Susans character well. But, I think Peter (in the new ones) said it best when he said "No, you're trying to be smart. AS USUAL." But, I will admit, that it kind of points to her eventual turning from Aslan and Narnia. All in all, I guess she did do a LOT better job.
Finally, BBC Peter vs William Moseley. BBC Peter looked like he was as old as(or rather as young as) the actor of Edmund!! He did an okaaayyy job with his character, but could have been loads better. Will, on the other hand, did a really good job pulling off his character. In the first one, he's the oldest in the family and has to take care of his younger siblings. As the oldest child in my family, I can relate, I'm always responsible for my younger brother, I love it, but I'm responsible. And then he becomes king of this magical world and is even more important than earlier. Then all that is taken from him and thats why he has more inflated pride and honor than most, and honestly, i would have reacted similarly. Moseley did a really good job playing this character.
All in all, the new ones did a lot better than the BBC versions in my opinion.