Update: Apparently, these are real.
Original story: A number of concept images, supposedly from Half-Life 3, Half-Life 2: Episode Three or whatever you want to call it, have been making the rounds. Needless to say, you should take a chunk of of salt with this one, but to have a look head over to AGB here. There’s quite a lot of them, over 30, showing off both character and environment ideas.
Valve, of course, is yet to say a word on when the next Half-Life anything would see the light of day.