Looks like episode 2 is not the end, theres more to it.
I found some Information on a half-life2 Site.
"What we know, and what to expect?"
We know the episode is going to be set in the northern reaches of the world of Half-Life, these will be cold places filled with ice and snow, oh and a Borealis.
The Borealis is that great ship that disappeared during some experimentation by the same sort of scientists that caused the Resonance Cascade from the original Half-Life. From what we have seen from Portal and the previous Episodes the Borealis is a scientific ship that was involved in teleportation tests at the Aperture Science labs. Something went wrong which led to the ship disappearing completely from its original location. It is only during the events of Episode 2 that we find out that it has returned, this time in the coldest reaches of the world.
I do not know anything about the release date for this game
Lets all hope that this game is better than a scorpion that can juggle bricks and it is mounted with Garry's Mod.