I've been waiting for this pretty much since it was announced, sometime after HL: Source turned out to be pretty meh.
Even in all the years after the failed-Christmas-release fiasco, I'd check back on the site every couple of months; there'd never been anything outright suggesting abandonment of the project, and they were still paying for the hosting and domain name, so I figured they'd just gone really quiet.
When I saw this counter appear on Saturday? Fangasm.
And Gribley; I'm assuming they'll have multiple download mirrors. They won't just have it on their site, they KNOW what'll happen if they try that. There'll have it in various places; mediafire, rapidshare, and other DDL sites, plus probably Fileplanet and almost certainly a torrent as well. Don't worry, you'll be able to get your hands on it easily enough.