Those who get the new game will be able to get the demo once it's released
Now, in order to cross-promote the two games, Sony has just confirmed, via PS blog, that all new copies of God of War: Ascension will include access to a special demo for The Last of Us.
Basically, those who get God of War: Ascension will receive special access into The Last of Us demo once it's released at a later date.
As of yet, Naughty Dog is still deciding what's going to be included in the demo and it's still unclear just when it's going to be released.
God of War: Ascension is out on March 12, in North America, and March 13, in Europe. The Last of Us is out on May 7.