Given the popularity of the previous Half-Life games, and Valve's news that the third episode would be the last one, you'd be forgiven for thinking that the developer would have a fairly firm release schedule in mind.

Did you know John Grisham doesn’t write his own books these days? He has ‘people’ do it for him. Actually, I don’t know if that’s true. It could just have been made up by someone envious of his success. Maybe I made it up