Thanks for the insights!
So both in Sudan and in Egypt (and in other Arab countries), it is used the same classical Arabic in books, songs, movies, comics...but at the same time an author might choose to use instead the dialect of his own country? There's any standard rule on this (I mean whether to choose one language or the other one) or it is only due to the personal choice of the author?
I will explain better
As I said, every Arabic country has it's own dialect that everyone in the country talk with it.
School books, newspapers and the news on TV are in classical Arabic, and you can use it to talk to someone from another country if you don't understand their dialect ( We can often understand other dialects easily, except for the Maghreb countries such as Algeria and Morocco ).
As for songs, books, magazines, movies It can be in the dialect or classical. ( For example, if someone decided to write a a novel, book or a song they are free to choose)
Our Mickey magazine in Egypt was for many years using the dialect, until some point when they started to use the classical.
That was in the old publishing house, the new one started with the classical directly.
So, It depends on the system followed in the magazine.