My DD appears to still believe. I suspect that she just doesn't want to admit that he is not real, but actually he doesn't buy all the presents in our house anyway. He gets one for each from their christmas list, their stocking, and the rest is from us, family, friends etc.
She asked me last year if he was real, and I, as another person did, asked her what she thought, and she said yes, she thinks so, but that some children at school were saying he wasn't real. She then saw some wrapping paper that DH used for a stocking filler as we ran out of the 'santa' stuff, and she asked 'mummy, santa doesn't wrap our presents does he? is it because he is too busy with so many children?' and i went along with it. But, actually, I think she wants to still believe, as she has a 6 year old who very much does believe.
The understanding of santa being fun is, and will continue to gradually sink in. I will not make a point of sitting her down and telling her the 'truth' like the facts of life, but as and when she asks questions, I will answer her truthfully.
However, as also said before, Christmas is not about Santa. It's about sharing, giving, receiving, spending time with family and close friends - the magic is about so much more than a man in red coming down a chimney. Those things will remain when they stop believing, and I expect we will continue to put out food and drink for him and the reindeers, and the children will continue to argue with daddy about whether he should have whisky or milk, even when they know!