A reference from John of the Cross' Ascent of Mount Carmel here related to this--sections 6-9.
Interestingly, I think that I lifted that, at least partially, out of Ascent of Mount Carmel somewhere, but I can't remember the specific location.
I thought it was that, since God was dead (that is, no longer given the central place in people's lives that had given all the other ritual accompaniments, such as a Christian morality, their power), that people would feel like they were adrift without purpose. Nietzsche goes on further than this though and says: if our previous morality has been cast off and we can see that there are other moralities possible, what is to stop us from deciding a new set of values for ourselves, one that makes us into what we want to be?
Interestingly enough, this new set of values will also form the basis for the criticism of other value systems-- including the previously cast off Christianity! (The Antichrist anyone?)
I think probably the most telling part of the passage you quoted was "Yet his shadow still looms". It does loom-- in the form of colloquial uses for the word "good", for example. As a contrast, with Aristotelianism there is not really an exact equivalent to the Western idealized "good". There is good towards an end, good related to existing as a human being, but not good-in-itself as is commonly associated with God.
This imprint of God on our culture is widespread, and it is no wonder that people who have decided to do away with God find it very hard to separate from his shadow, as I mentioned in my first post. It is a bit more complicated than just saying, "I don't believe."