So a mysterious update for portal has appeared:
"Changed radio transmission frequency to comply with federal and state spectrum management regulations"
And if you pick up a radio while in game and stand in a particular area with it (such as the button in the first room) you start getting a stream of morse code!
A secret message? Portal 2? Episode 3? Come in Dr Freeman? Valve messing with us? Who knows!
I'm off to bed right now but I'm hoping it will be figured out by those clever American gamers by the time I wake up...
Looks like guys from several different forums have been busy. I've been reading up on what the steampowered forum peeps have been looking at specifically and it does appear that there are hidden messages behind all of this.
If you're like me and it's too much trouble to work out on your own, then check out this thread from the steampowered forums which has decoded the radio transmissions from the game into images and also has a link for the translated morse code transmissions.
Overall I don't believe there's anything specific thats been discovered yet aside from these images and some ASCII art pulled from a "secret" BBS location. I'm sure these guys are still working away at it all and if there is a conclusive message to be discovered, they'll find it!