You really think they would put “We’re committed to releasing in the year 2009” on the new main page if they didn’t think they were going to make it?
Also, I don’t see any reason as to why they might not delay the game a week or so just for the sake of releasing it on Half-Life’s anniversary. It gives them a small grace period, and a chance to make sure there aren’t any serious last-minute bugs. I don’t think that’s a valid argument against a 19th release. Not that I really think it will actually come out then. 

