Well, at this point, nobody really believes that any one of those games would actually be released in the near future but Valve has just made it even clearer when they announce that Erik Wolpaw has left the company.
In case you are wondering, Wolpaw was the guy that co-wrote some of Valve’s most popular games including Left 4 Dead, Half-Life, and Portal. Wolpaw posted on his Facebook page that he is not working for Valve anymore.
With him leaving, chances of us seeing a new release of any of those games is even slimmer now. He did not reveal why he wanted to leave Valve.
One of the reasons why fans are still begging for a sequel to those games was because those games were not given a proper ending. It was clear that Valve had plans to do more with those games but then decided to change their mind later on.