Director Rich Moore, who also directed Zootopia, made the official announcement yesterday straight from the Disney Animation Studios via Facebook live video, saying that he's returning to direct the sequel together with writer Phil Johnston as co-director. John C. Reilly, who voiced the titular character, also appeared in the live video wearing Ralph's fists--a dead giveaway that the sequel is a go. Sarah Silverman is also confirmed to reprise her role as Vanellope von Schweetz.
A number of characters from popular video games made cameos in the first movie, including Sonic and Dr. Eggman (Sonic the Hedgehog), Zangief, Ryu, Ken, Cammy, Chun-Li and M.Bison (Street Fighter), Bowser (Super Mario), Clyde (Pac-Man) among others. This time in the sequel, where Ralph and Vanellope are set to jump out of their arcade world to wreck the Internet, who knows if we're going to be treated to our much-requested cameo by the one and only Mario.
Wreck-It Ralph 2 is set to be released on March 9, 2018.
Additional source: Oh My Disney