I feel like the meme about Half-Life has passed the point of being meme-able. Those that played HL1 and 2 and the Episodes are likely not even playing many games now. To announce a HL3 game now after an embarrassing amount of time when the technology for an amazing sequel has been around for ten years or more, when Steam has already become the global PC platform for games and they've made far more money focusing on that and games like CS, when gaming is not in a great place, when it's been so hush-hush for so long (basically no leaks as far as I can tell), it just doesn't make sense.
But hey... maybe...