Jake Howell has a speculative post about Cannes. All the usual suspects (Assayas, Cronenberg, Hazanavicius etc.) are in his list but he also mentions some interesting possibilities.
http://moviecitynews.com/2014/02/divining-cannes-2014/
Fincher, David – Gone Girl (October 2014)
Malick, Terrence – Voyage of Time or Knight of Cups (2014, post-prod)
Miike, Takashi – Kuime (2014, completed)
Miller, Frank and Robert Rodriguez – Sin City: A Dame to Kill For (2014, post-prod)
—Angelina Jolie is a red carpet favorite at Cannes, and her film Unbroken (2014) is undoubtedly being courted by the Festival.
—Had I included 2002’s Festival in my research, Paul Thomas Anderson’s Inherent Vice would appear above. The film is indeed expected to debut at Cannes.
—Coincidentally, Gavin O’Connor’s Jane Got a Gun is set to be released on August 29, 2014—exactly two years after the theatrical release of John Hillcoat’s 2012 Competition film, Lawless. Seeing as The Weinstein Company is responsible for both of these Westerns, Jane Got a Gun is almost assuredly going to Cannes—assuming they follow the same release strategy as Lawless.
David Ehrlich doesn't think Gone Girl will debut at Cannes
david ehrlich @davidehrlich 53m
@Jake_Howell @firstshowing gone girl will definitely not play there, the new assayas film definitely will