Sony's response (via MovieLine): "The DVD and Blu-ray come out on Jan. 12 — next Tuesday — and it was felt that to preserve the integrity of the film, we didn't want to send screeners. We're concerned about piracy. The thing about Moon is that its particular genre is very predisposed toward being uploaded onto the Web. We really just wanted to protect that aspect of it. I'’s a simple as that. […] A lot of publicity for Moon is coming out next week. Hopefully that will remind all the consumers, all the readers — and especially any awards folks — that this terrific title is out there."
That is all good and well Sony, however, it is notable for me to publish that DVD copies of Moon have been available online since late October, and Blu-ray copies have been available since November.