Users of the new Source Filmmaker have found out that there might be a new engine by the name of Source 2. These users dug into the code of Source Filmmaker and found multiple lines of code that could be leading to a new engine named Source 2. "Return an str with the current engine version. If key doesn't doesn't exist, assume 'Source', otherwise invalid -- assume next-gen 'Source 2',", is one line that was found among the code that leads these users to believe that Source 2 is being made. Valve has made no official comment on this yet. This could be the reason why Half Life 2 Episode 3/Half Life 3 news has not been talked about in such a long time. I kind of expected something like this to happen. If this turns out to be true, it would be a great idea to use this engine on HL2 EP3/HL3 for the first game that they use it on.
Full Article: http://www.screwattack.com/news/rumor-source-filmmaker-might-have-revealed-source-20