Half-Life is one of my favorite games ever, and after fifteen years on the market, the Sven Co-op team have been granted full access to the standalone game based on the mod.
This means that the team will modify the engine to their liking, going as far as adding new features that should provide stability, performance and even gameplay improvements to all. We should expect bigger and more detailed worlds, with automatic updates delivered through Steam's content delivery system, 'SteamPipe'.
Better yet, Sven Co-op's next version of the game will be free and will include the official Half-Life campaign for co-op play - oh, yeah. If you don't already own Half-Life - and let's face it, if you don't, there's something wrong - you won't have to purchase it, as this version will be free. No ETA has been made, so we don't know when to expect it at all unfortunately.