Allocine interviewed Lambert Wilson for the release of his upcoming film, The Translator. During the interview he said that his character that appeared in The Matrix Reloaded and The Matrix Revolutions, The Merovingian, is in Matrix 4. He has been contacted by Warner Bros. and Lana Wachowski and is in talks for the role. However, he may have a scheduling conflict that may keep him from participating. Info about the character from the article via the google translator is below.
The Merovingian is an information trafficker with a pronounced French accent. He shows an immoderate taste for profanity in the language of Molière and everything suggests that his birth came very soon after that of the Matrix, and that he would survive each of its new versions while keeping some of its programs. In Reloaded, he is the one who holds the Master of Keys (Randall Duk Kim) capable of leading the heroes to the source of the Matrix; and in Revolutions, he controls the intermediate world in which Neo is held captive.