Yeah I made a topic about this earlier, but if I remember correctly it was over a year ago and I can't find it. :S
Anyway, today there's been a new development: A countdown clock has appeared on the Black Mesa Source website:
http://www.blackmesasource.com/
12 days, 8 hours until release at time of writing this, so definitely, definitely coming soon. Finally. After 8 years of me waiting for this. But kudos to the development team who have made this thing in their spare time and stuck to it for that long despite entire team shifts, level re-designs and changes in direction... And it's looking really incredible so far for a
fan-based, unofficial hobby project, which is what some people like to forget. It's an impressive feat of game development.
This is an interesting article about their development process and the problems they've faced over the years.
Here's some screenshots: