The NDA referenced earlier has expired, and the first web-based Half-Life 2 previews have begun appearing. There are now previews of Half-Life 2 in (alphabetically): Computer and Video Games, GameSpot, GameSpy, PC.IGN.Com, and Shacknews, . Each article is based on seeing a some proof of concept demonstrations, offering their individual impressions and a shared pool of screenshots, which are also posted here locally. There are also plentiful developer quotes scattered throughout, offering the first details about gameplay in the shooter sequel. Here's a bit from the GameSpot article, as we're impressed by how the NDA seems to have been crafted to fit the big dog's daily publishing schedule. They refute some rumors and shed light on the game's true target platform:

In case you were wondering, the game is also being built, first and foremost, for the PC. Leading up to the official announcement from Valve that Half-Life 2 would be publicly displayed for the first time at the Electronic Entertainment Expo in May 2003, rumors spread far and wide about what the game would and wouldn't be. One of the more popular rumors was that, much like how Bungie Software moved development of its outstanding first-person shooter, Halo, from the PC to the Xbox, so would Valve switch to focusing on console development. Newell laughed this off--no, Half-Life 2 will be a PC game. At first. Newell did confirm that an Xbox version, at least, will follow suit, though there's no hard release date for it yet. At any rate, Newell emphasized that the success of the original Half-Life can be attributed in no small part to the game's huge, worldwide following of PC owners. Valve would have to be downright foolish to abandon its huge installed base when making Half-Life 2.