The late Dr. Malachi Martin has written, in "Vatican", a lengthy, well-sustained "novel" about the intrigues of the Holy See from 1945 until the mid 1980's. However, in many respects, this is not a work of fiction, legal disclaimers notwithstanding. These are real characters, given false names, but functioning much as they actually did in real life. Around this, is a cleverly woven plot of conspiricy, heresy and murder which is fictional (or at least conjectural in the mind of the author!)
It is clear where Martin's sympathies lay -- and they were not with the modern Church. However, as the book was written in the mid 80's, and Martin very obviously expected Pope John Paul II to die in that time frame, (and considering that Martin himself is now dead), it is impossible to conjecture whether or not he had a real person in mind for his novel's ending.
As a public service, here is a brief comparison between Martin's "fictional" characters, and their real-life counterparts:
Papa Eugenio Profumi -- Pope Pius XII (Eugenio Pacelli)
Papa Angelica -- Pope John XXIII (Roncalli)
Papa DaBrescia -- Pope Paul VI (Montini)
Papa Serena -- Pope John Paul I (Albino Luciani)
Papa Bogdan Valeska -- Pope John Paul II
http://www.amazon.com/exec/obidos/tg/detail/-/0060154780/qid=1110295127/sr=1-1/ref=sr_1_1/103-1061657-6857446?v=glance&s=books
Wait a minute....St. CLETUS?
A Southern Pope?