I just got the invite, and the press conference will be held in Santa Monica this time around. Amazon is breaking with their past habit of scheduling launches in NYC. I'm still thinking about going, but if I do I expect to see that 10" Kindle Fire, a new Kindle, and the new dock for the Kindle Fire. That last item is going to work with the larger KF, I think.
The new location suggests other possibilities, like a greater emphasis on the media abilities of the KF. That would fit well with the new dock.