Reports have indicated that the Russo Brothers will be directing both parts of Avengers: Infinity War.
Joe and Anthony Russo directed Captain America: The Winter Soldier and are about to begin work on Captain America: Civil War. They will be taking over the Avengers franchise from Joss Whedon who directed the first two installments.
Avengers: Infinity War Part I is set to be released May 4, 2018 with Part II being released May 3, 2019.