They must have got their dates wrong - I'm not due to go again until April
In all seriousness, I think they're guessing at a possible war in Iraq, hence they are being as security-conscious as possible. The simple truth is no-one (outside the Pentagon and White House, presumably!) knows, so they are just trying to be ready. The only real affect for transatlantic travellers will be the extra time you need at check-in and security screening both ways. I'm afraid turning up an hour before your flight is not a recommended scenario these days.