"Petavius (De Incarnatione, I, xii, c. 4) maintains that there is no controversy among theologians, or even among Christians, as to the fact that the soul of Jesus Christ was endowed with the beatific vision from the beginning of its existence."
Catholic teaching holds that Christ our Lord saw the Divine Essence of God in His created soul from the first instant of His Incarnation. As an act of condensation, Christ prevented the glory of this vision from overflowing to His sacred body. He only allowed this to happen once before His resurrection - at the transfiguration on Mount Tabor. Christ also prevented the glory of His beatific vision from overflowing to the lower faculties of His soul so that He might experience sorrow and pain, as in the His dolorous Passion (Summa theologiae III, q. 13, a. 5).
The Catholic belief that the blessed shall enjoy the Beatific Vision follows from the fact that Christ enjoys the Beatific Vision in His soul. By being perfectly conformed to Christ, the blessing of what Saint Paul calls being "in Him", we share in His inheritance.
I'd be interested in whether the Byzantine tradition also holds that Christ saw the Divine Essence of God in His created soul.
 Maas, A. (1910). Knowledge of Jesus Christ. In The Catholic Encyclopedia. New York: Robert Appleton Company. Retrieved April 13, 2009 from New Advent: http://www.newadvent.org/cathen/08675a.htm