This is hearsay, but I just heard from a friend who is waiting for 3 D3's that his client ordered, (December batch as far as I know) that after they contacted Bitmain complaining about the D 3 situation, Bitmain offered too keep their money in credit and they can then order other machines next year when available and only pay the difference, if there is any.
He will send me the mail from Bitmain as soon as he receives it from his client.
As I said this is hearsay at the moment.