Mysterious Portal-patch released

Valve released a really mysterious patch for Portal on Steam yesterday, with the patch notes only containing the line ""[c]hanged radio transmission frequency to comply with federal and state spectrum management regulations". A new achievement called "Transmission Received" has been added to the game as well, which is unlocked by placing the radio on the red button in the first level according to Shacknews.

If you do that, the radio starts spitting out Morse-code which has been translated to:

Interior transmission active

External data line active

Message digest active

The quick brown fox jumps over the lazy dog

System data dump active

User back up active

Password back up active

Beep beep beep beep lol

Also, the following hidden images have been found in the updated game files. What's going on? Can we expect more news about Portal 2? Or is there something else going on? I'm not sure I trust GlaDOS...