Anyone who has been unsuccessful in getting the Crysis demo using FilePlanet should be glad to hear that the demo will be publicly available to everyone in just over 12 hours (12 hours and 47 minutes as I write this). An in-official site which is counting down to the launch can be found here, although the servers will probably struggle to cope with demand at first given that Crysis is one of the most anticipated games so far this year, so it may be worth waiting for a few external sites to start hosting the demo. Anyone who has already ordered Crysis via EA should be able to download the demo already via EA's downloader.

Update: Unfortunately EA has decided to delay the public release by an extra day, so it's now going to be released tomorrow. Sorry for the disappointment, from a quick look it seems the delay could be linked to issues with the 24 hour exclusive for customers purchasing Crysis via the EA Store.