I was filmed talking about Oni's presence by Phil (MCD) yesterday, it's finally up and you can watch it here (approx. 7 MB).
I was lucky enough to meet Doug Myres who works at Gathering of Developers whom I asked a couple of questions. When I asked him why there was no playable build of Oni, he told me there was nobody available to demo the game, and GoD has no actual booth because they were able to show off games at the 3DFx booth.
Doug also told me that Bungie will handle support and patches, while GoD does marketing.
I may not update this page anymore due to the fact that there is no real Oni presence.
Well, my first time at MacWorld, and it's amazing. Oni's presence is very minimal, the 3DFx booth is showing the E3 2000 trailer, and that is it. I was unable to find the booth of Gathering of Developers, maybe they're here tomorrow.