In the midst of bad news, there's still some good: the single-player extension will be free, and the multiplayer mode will support microphone use, so you can taunt other players online: "Good news is, we have the all clear to make Chapter 5 a free download. We have been expecting this and have been 99.9% sure it would be, but we could not announce it without the blessing of the higher ups. Also I want to confirm that it will allow Voice comms for those with headsets, but that is all I want to tell you about it right now. "
This Killzone patch cannot come soon enough.
Killzone: Liberation downloadable demo