Even though Portal 2 is official, Valve isn't done messing with its fans' heads. While the company issued a very brief release today regarding the game, a hidden message was planted in the text. Here's the announcement:
Steam forum members quickly decoded the underlined parts of the message to discover a password combination that produced the following set of images, adding even more intrigue to Portal 2's multiplayer.
Today's developments have made three things very clear--Portal 2 is coming, Valve isn't done messing with our heads, and the fans are ready for whatever mysteries are thrown at them.
SOURCES: [Game Informer], [GameStop], & [Steam Users' Forums]