Ahaha I am so waiting for the inevitable party for the announcement and/or release of the next Half-Life game.

Valve has released concept art for it a while back, I think right after ep 2 came out (in 2007). There are only a few pieces of art as far as I remember ;3; and every so often we will get notes from Valve saying "there WILL be another HL game, be patient!" the most recent being a few months ago I think.