"What Would VALVe Do?" is a rhetorical question that one asks a video game company. It questions whether or not a course of action that a video game company is or will be taking is something that VALVe - a popular video game company that many gamers believe does everything right - would do.
WWVD is usually a chastising remark, meant to rebuke a company for a bad decision.
Why do we have to pay so much for DLC? Why not include it in the game, or as a free update? What Would Valve Do?