Just to collect some of the recent Oni revelations in one place. On the Oni Central forum there's been a lively discussion about an Oni demo, whether or not there will be one, and when, and for what machines. Matt Soell basically said in his post that everyone is busy finishing the game and we should ask about the demo later.
However, assuming the Mac and PC versions are still on-target, there should be about two weeks between when they are done and when all three versions will be released, as the Gathering Of Developers has decided to hold for a release simultaneously with the PSX2 version.
Aside from that, there's more going on: G.O.D. is holding an Oni fan art contest, as announced by Shane in a post on the Oni Central forum. The deadline for submissions is January 8; check the entire thread out for all the details.
There's also a thread on the Oni box art that people have been seeing at Amazon.com; according to Matt it is definitely Konoko, although the artwork itself was apparently not related to anything done by Bungie.