Now you know Portal as well as I do, and you know Valve... so you know it's never simple. Notice that the Steam announcement has random characters underlined? Yeah. That's a login and password to some bulletin board. There's a whole slew of people tweaking away at this already. The recent update to the game included some oddly named wave files which turned out to have CCTV images hidden in them, there's a bunch of ascii images from the bbs login, and apparently a bunch of gibberish is actually a proprietary image format that can be interpreted in basic. Needless to say, I'm effin lost.
The people who know what's going on, or at least are figuring it out as they go along, are updating this wiki.Oh, and they modified the ending to the first game.
Details I've gleaned so far: the release date is possibly October 22 this year, GlaDos survived (we knew that from her song though, but now we know her "body" wasn't destroyed), and this time we will get to use the portal gun outside, and there might be a co-op mode.












