Before you watch the video below i must warn you. It shows Portal's new ending. Yup, that's right, Portal has a slightly diferent ending sequence now. I suppose you have to unlock the "Transmission Received" achievement in order to unlock this new sequence. It completely changes the perspective on the history, where technically we had no proof we would have survived the ending. It's never too much to give you another heads up, the following video will most likely ruin the final of your Portal experience. Don't watch it if you haven't played the game yet. At least once.