Reuters headlined their story on the terror attack thus:-
New Jeruslem vehicle "attack" as Livni seeks govt
The indeed is an Old City, because it is within the walls which were built in 1520-30, and the so-called "New" city is that which started to be built in 1854.
But since 1967, it is one city. One unified city. Reunited after the Jordanians split it in 1948 for it was to be a corpus separatum.
There may be "new neighborhoods" but no "New Jerusalem".
Jerusalem is 3000 years old!