The delay is most likely a marketing ploy (by Sony not Polyphony digital) or something like the damage modeling is taking longer than expected. Whatever it is, we'll probably see a simultaneous worldwide release now.
Overall though, I don't see what all the fuss is about over it taking sooooooo long.
Think about it.
They only have 110 staff.
It takes, on average, 4.5 months to completely model a car, inside and out.
By my calculations it would take almost 4 years to model the 1000 cars alone, and that's not including time taken for track/scenery modeling, interface development, online capability, damage programming, and the physics engine.
Besides, they'll even be announcing a new manufacturer at TAS.... This from GTPlanet....