As previously announced, the trailer confirms that the the mod will be coming to Steam as a standalone game. The 5.0 release will be free, and will not require any of the Half-Life games installed to work.
Sven Co-op was originally released 17 years ago in 1999. The mod allows users to play the entire Half-Life campaign in multiplayer co-op, and has had a ton of community made maps released specifically for it. You can download the current 4.8 version here, but you’ll need the GoldSrc version of Half-Life to play it.
Nih, one of the mod’s developers, stated that more media and information about the 5.0 update is to come in the near future, so stay tuned.
You can find more detailed information about the 5.0 update in the meantime on the official Sven Co-op website.