The Crysis demo has been officially delayed. Here is the announcement by Cevat Yerli, President and CEO of Crytek.
"First, I am sorry for the bad news - the Crysis single player demo will now be available everywhere on October 26th, 2007. We are taking some extra time to make sure you that you have an amazing experience but also we did not want to risk the release date of Crysis at this stage. To get the game into your hands by November the 16th, we had to make this call"