Well to quote Vanjoki in that very article: "but a Symbian^4 Nseries device is a strong possibility. A very strong possibility ;-)"

So why couldn't this be it?

There's just so many things about this device that ring to me as a Symbian device. Still thinking back to that "leaked ad". That was Symbiansymbiansymbian to the core that ad with the way it looked.

Also, this is supposed to be the coming of the Nokia MeeGo device, the device that will take over America and Europe. Wouldn't they want to make it stand out amongst Nokia's Symbian models? I don't think that they can afford the risk that people associate that form factor with Sym^3.