Note that the first 4 hours of the event is a presentation "Nikon depth technical news" by Nital (the official Nikon distributor for Italy).
Not convincing enough, right? Well, there is another Nikon event in the Los Angeles Convention Center scheduled for December 3-4, 2011:
Update: the event in LA is for the Nikon School.
And another event scheduled in a Canadian store for December 2-4, 2011:
There are similar events scheduled for December 2-4 at some stores in the UK as well.
It is not likely for Nikon to announce a new product on a weekend (December 3rd is a Saturday) but this could very well be the product introduction/demo events after the announcement (similar to the many Nikon 1 events).
First week of December is also the last chance for Nikon to announce a new product for 2011. Historically they have never announced a new product past the first week of December.
As of today, I do not have any information about a scheduled Nikon press conference in the next few weeks.