I'm actually pretty sure they are working on it,
Though i think they want to "avoid" the thing that happened with episode 2, where they showed a trailer and new footage in the finale of EP1 and then had nothing of that be actually true in the EP2 that came out years later.
Also one of the devs at valve once slipped up in a very subtle way,
As he was talking about how he loved the L4D2 production since it went very fast and organised.
After wich i sarcastically commented that i would then love HL3's development.
On wich he replied that he isn't involved in that.
My conclusion being, if he is "not" involved then there is also a way to be involved.
Explaining there is a game in the making...
Though i think they want to "avoid" the thing that happened with episode 2, where they showed a trailer and new footage in the finale of EP1 and then had nothing of that be actually true in the EP2 that came out years later.
Also one of the devs at valve once slipped up in a very subtle way,
As he was talking about how he loved the L4D2 production since it went very fast and organised.
After wich i sarcastically commented that i would then love HL3's development.
On wich he replied that he isn't involved in that.
My conclusion being, if he is "not" involved then there is also a way to be involved.
Explaining there is a game in the making...