I'm guessing Nokia is struggling to get N9 to the production line and after saw the competitions hardware specs, Nokia hold the N9 back and revise one the current specs and making some adjustment before conclude the final prototype.
On the other hand Nokia may be working really hard trying to get the bugs out of Maemo6 OS meeGo to run on their current leaked prototype.
Nokia isn't saying because saying things now will make the competitors attacking them directly with hardware and OSs. Android is currently the strongest competition and iOS is the front of the line of competition. So I'm guessing we would be lucky if Nokia decides to put A9 in the N9 at the production spec.