Okay look. Everyone is claiming 'Oh Zombie Apocalypse oh no! Whatever shall we do?'
The fact of the matter is this. This dude that issued the 'Apocalypse' date, he predicted the same thing back in 1994, maybe not with zombies, but it was something similar. Now I don't know about you, but it's 2011, 17 years past his last assumption. I'm still alive and kicking and odds are if you're reading this you are too, unless you're a pretty smart zombie, then I give you props, you must've chowed down on quite a bit of cranium lately. Good for you.
The reason CDC made the announcement is because it was a way to get a message out there. What better way to help people know how to prepare for a natural disaster than attacking the concept while another concept, one almost everyone knows and fears if they are a gamer (regardless of platform), and teach it that way. CDC is trying to get people to learn how to prepare for natural disasters. Because the same things that you would do to prep for a zombie invasion would be the same that you would do for an earthquake or hurricane or blizzard even.
Extra food - No duh. You gotta eat at some point and time and eating your fellow survivors isn't smart.
Extra water - Because no one likes to drink their own urine
Toiletries - (Toilet paper and what not) Because if you don't have this, odds are you'll wipe with something that you shouldn't. Like poison ivy. So take your pick. Carry a few extra rolls of Charmin, or have an itchy bottom. Not too hard.
So really, it's not a big thing to worry about, CDC is just going with the publicity hype to get people to realize 'Hey. I need this stuff in case of emergencies'. Other than that, will the zombie come devour our brains? Possibly. The best cure? Grab the shotgun off the shelf and start shooting. But really, there is almost no reason to worry about this. It is something foolish to tap into common people's fear and make them freak out.