Not so says Valve, it was more than just fun on the art team's part. They've gone and got full permission for tunes, swag and likenesses from the band and everything. Perhaps a cameo?
Left 4 Dead 2's Chet Faliszek says Valve blanketed a load of record labels and bands to get in on the Infected action but Depeche Mode was one of the few to return their calls, reports.
They were completely open to letting the devs run amok with their tunes and likeness in the sequel, Faliszek revealed at Comic-Con. Hopefully we could see a tongue-in cheek cameo?