I think the only proper way to release games is the shockwave principle. You heat it up, then it burns, and quickly detonates.
Space Rangers was a great hit here in russia because it was good, and nobody even suspected that the game existed right until it hit the shelves. Not even Starforce repelled people from the game.
I think that a good game must be announced - "heated up" - only once it hits the first beta stage, around a month before the planned release. People will start discussing it, throwing ideas around, mostly thinking the game is still far off, especially if it's good. If all goes well, and the game as it is now conforms to the expectations of the people, around a week before it goes gold the second stage - "burning" - should kick in, screenshots, movies, and interviews must be shared, but the release date must still be shrouded in mystery. Hype will build up due to released details, and people will start waiting for the game. It'll be nigh impossible to contain the info if the game's true state anyways, so as soon as it's apparent that the "conspiracy" is revealed, the third stage - detonation - starts, the game is released worldwide and electronically, demos, reviews (pre-obtained, of course), and all supporting sites and all other bells and whistles are unleashed upon the public. It's important that the release is worldwide, and electronic, and that there's no intervening barriers like copy protection in the way. A good game that's suddenly released everywhere and has nothing stopping a player from enjoying it will hardy get a high piracy ratio, because there would be little incentive to get the game illegally, other than cost, but that one can't be mended it seems - people are always greedy and money-grubbing.