New Half-Life game by December 31?

This market will resolve to if Valve publicly and explicitly announces that a new Half-Life game is in production by the specified date, 11:59 PM ET. Otherwise, this market will resolve to "No". To qualify for a "Yes" resolution, the game must be explicitly acknowledged by Valve to be an installment of the Half-Life franchise or have the words "Half-Life" in the title. Updates to and expansion packs for already-released games will not be sufficient to resolve this market to "Yes". An announcement by Valve of a new qualifying game before this market's end date will immediately resolve this market to "Yes", regardless of when the announced game becomes available to the public. The resolution source for this market will be official information from Valve or a consensus of credible sources.