I used to know a mapper that was working on this, back when it was named 'Black Mesa: Source'. I think the project died out completely for a while, as most of the team seems to have changed completely. Given how many times it has been put on hold, I wouldn't trust that release date.
As far as I'm aware the only date they missed was the 2009 one and since then the devs have refused to discuss a release date in even vague terms...until now of course. So I think that date is fairly solid.
Ah and for anyone who wants this mod to be available on steam; here's the Greenlight link
and be sure to vote yes!
Public release dates maybe, but I know that lots of their internal targets have been missed/ignored over the years. Most of the content in the mod that was supposedly 'finished' back when I used to follow its development has long been scrapped.