The PlanetHalflife guys have the full preview of The Orange Box titles Episode 2 and Portal up. Check it out, it’s a great read and has some more new screenshots.

Portal offers Half-Lifers a more unique challenge experience when it comes to the games they play. You won't be mowing down combine or saving the world from oblivion, but simply having fun and challenging not only the game, but yourself as well with puzzles. Any age can play this game and have fun, and you soon find out how addicting the game is. The only thing that could tear me from Portal during my playtest was Episode 2, and I really had to use the bathroom by that point too… it's pretty easy to get lost in Portal.

Anyone else notice they misspelled Aperture Science? Hah!