It's not really the media's fault, given they're taking it very light-heartedly (at least here), with smiles on their faces. For serious things they just... don't. I'm not sure why someone in the media WOULD actually make it come across seriously as that's not ethically right (or allowed in the law, unless it's for certain, iirc from my media law and ethics book). ;(
The Internet and word of mouth is definitely the most problematic thing of all, though. That's what's causing the hype which is kind of greatly irritating, considering how easy it is to spread fake information around the Internet, while in the actual media, stuff like that needs to be treated a certain way. The media knows if they definitely report on the end of the world as in "the end", then they'll just be causing mass hysteria, and possible suicides. It just can't be done that way. Anyone taking the media's messages about this seriously should really... think about their lives.
Still, if it helps, I'm going into journalism soon (if I can get a job when I start looking soon :x) and I wouldn't report something like that seriously, but yeah.