WATCH OUT! That valvetime.net site is infected! (probably the ads) My antivirus is going nuts when I go to the valvetime.net site. (probably all the traffic some script kiddie saw his chance)
The episode 4 thing I think is made up.
This link has more details: www.rockpapershotgun.com/2013/01/14/wuh-valve-had-arkane-working-on-episode-4
If you RTFA on the RPS link, sounds like it was meant to be ep 2.3
Return to Ravenholm was to be a standalone episode set between Episode 2 and Episode 3 that Arkane were working on as far back as 2006, and would bring the players back to the wrecked, zombified mining town. [...] the fact that it would have to take place sometime before the end of Episode 2 (so as not to advance beyond where Valve had pushed the story)