After intense speculation, Ferrari has finally given confirmation that the 599 GTO will be released.
Basically, the 599 GTO is a road variant of the racecar Ferrari 599 XX.

Interestingly, this is the first time that Ferrari has used the GTO nameplate since the 288 GTO, which was built from 1984-1986. Ferrari CEO Amedeo Felisa, who confirmed this news through Evo Magazine, said that the classification of the 599 GTB Fiorano has been changed from “GT” to its “Sports Car” designation, allowing for the development of this extreme GTO version.

Source: autospies.com