Since the full Source SDK is now available, we at Sven Co-op thought this might be a good time to let everyone in on some of our plans for Sven Co-op 2.
First of all, I should mention that we'll be focusing on the basics for the first release: Establishing smooth, fun cooperative gameplay, and allowing level designers to start working on co-op maps. Features such as new monsters and weapons will be coming, but mostly in subsequent releases. Trying for too much at once would only delay things in the long run... and anyway, this way you'll have something to play while waiting for multi-user vehicles/etc.
Cooperative support for the Half-Life 2 single-player storyline is something that has been requested by a great many people, and as such, it is one of our priorities. Some changes to the maps will be necessary in order for cooperative play to work smoothly, but we will strive to keep things as true to the original experience as we can (another thing that has been heavily requested). Partly in the interests of this -- and also due to performance issues, balancing issues, and the fact that the maps were simply not designed with large player counts in mind -- the maximum player count for HL2SP maps will likely be fairly low. Higher player counts will be supported for cooperative maps.
More details, including information on Sven Co-op 2's flexible mapper-defined class system and a major change to Sven Co-op's fundamental gameplay, are available at SvenCoop.com.