The new Call of Duty game, seventh in the best-selling video game series, is to be revealed on the North American website GameTrailers and its weekly Spike TV show, going live early in the morning of Saturday, May 1.

According to rumour, though most of the Call of Duty games have been set during World War II, Call of Duty 7 is to be situated in the Vietnam conflict.

The preview comes at a time when Infinity Ward, the most successful Activision studio involved in the Call of Duty / Modern Warfare franchise, is mired in turmoil ever since their two top dogs were fired by parent company Activision and have since started setting up a new company, Respawn Entertainment, in partnership with competing publishing giant Electronic Arts. (Infinity Ward wasn't the only studio working on the Call of Duty name: Treyarch, the developers of Call of Duty 7 had been putting out a CoD game in the years that Infinity Ward didn't.)

Activision, meanwhile, has since established a new wholly-owned studio, Sledgehammer Games, to make an action-adventure variant for the franchise. With this being in contrast to the series' fixation with the first-person shooter genre, some now believe that a massively multiplayer game is on the cards, mirroring the success of another company property, World of Warcraft.