VG247: Johnathan Kessler, the manager for Depeche Mode, has told VG247 that the band's inclusion in Valve's Left 4 Dead 2 was a way to get their music out to a younger generation.
"There is no storyline in the game with the band, as they do not appear in the game," Kessler told VG247 exclusively." Their music was included as a way to get their songs out there, so that the kids can be exposed to it in a way that differs from conventional radio."
As far as this being a stepping stone for the band to possibly be included in Rock Band or Guitar Hero in the future, Kessler says that there are "no plans for that at this time".