UPDATE2:
Jesus Christ, more shit is coming out from their research, stick to the thread link I posted. This is crazy.
UPDATE:
Holy shit, the Steam forum members went fucking Sherlock about this, and managed to pull out a GLaDOS ASCII image from both the SSTV files and accessing the restricted BBS found in the hints given accessing in a modem.
(https://clockcrew.net/talk/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FsNO9z.png&hash=9a6d87de4f4e0dbb173452b6c78024fbced605d4)
(https://clockcrew.net/talk/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FPAKSf.png&hash=a299cb3061a351eb0f265dbd62f2f7efbbc0c248)
Also judging by the version of GLaDOS on that image (3.11), it is speculated we will know everything in March 11. Gabe Newell will be given an award on GDC.
Shit just got DaVinci Code.
Today Portal got updated with a new achievement on Steam, simply titled as "Transmission Received"
You can look for the radio for different signals, and they got decoded by Steam forum users.
http://forums.steampowered.com/forums/showthread.php?t=1169218
There are even hidden SSTV images in the audio files, and they have some strange clues.
The video below is one of the files.
[u2]vt3uog2tKAQ[/u2]
Eerily, they say that Half Life 2: Episode Two got updated as well.
Dun dun dunnnn
omfg
VIRAL MARKETING
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyay
You guys should check out the whole stuff on the Steam forums, I cannot believe how much was discovered with only audio files.
(https://clockcrew.net/talk/proxy.php?request=http%3A%2F%2Ffiles.myfrogbag.com%2Fx0quzz%2FGabed.png&hash=831ddd3888d923174eb562d5d5844c1d8b80a7f7)
Jesus fuck, Valve is good at this
Valve recently hired some devs from Naughty Dog
so that's pretty fucking awesome
http://www.joystiq.com/2010/03/12/valves-viral-plot-thickens-with-portal-blue-screen-of-death/