on the Tokyo Revelations website.

chibiyuuto has a recent internet radio show up where CLAMP corrects Miyu Irino (Syaoran's seiyuu) when he called it an OVA/OAV. They are calling it an OAD (Original Animation DVD).
'OAD' it is; though the character sketches have ova written on them.

and also via chibiyuuto, Animedia interview w/ CLAMP translated by usomitai

( and the tracklist from the recent Internet Radio book )