A user from japanese discussion boards 2ch received the XXXHOLiC Rou Short-OAD and reports that a new OAD for XXXHOLiC Rou, expected for the Spring of 2011, was announced in it.
Here is a screenshot from the announcement:
Update: The short-OAD is actually the Opening sequence of the new OAD featuring a song by Suga Shikao.
Update 2: Pictures from the short-OAD were posted on Yahoo Auctions:
The package says “Opening movie of the new OAD”.