Alright, while this page is to 99% fake, it's true that there are many hints for Half-life at the moment.
To name a few, the hl3 T-Shirt worn by a Valve employee or when you write "status" on a Valve tf2 server it says "Gordon", or for the Steam translation an example by Valve for gamerecomending "I really like Half Life 2: Episode Two, but it doesn't really feel like the end."
I've been debunking them as mere coincidences or just fans seeing things, the last few weeks.
But there are just too many now.
Also, this happened today: https://twitter.com/#!/Steamcast/status/149415750623432704
This guy is one of the three hosts for the "Steamcast Podcast" in the ep2 subforum on the Steamforums.
He was also heavily involved in the Portal 2 ARG and got called by Valve to go to Valve HQ and became one of the "kidnapped" people. He's a reputable person and wouldn't troll he hl fans because he is also one and knows how hard it is for hl fans.
So I believe him, he doesn't have a reason to troll us.
This means that we'll see a lot more hints about Half-Life in the next few months and e3 2012 is a big candidate to announce the game officially.
This would also mean that it won't take much longer for the game to be released since they mostly announce their game when they're in the finishing parts. I'd say, it won't take more than a year or two at most.