According to the scientific community there's no reason to freak out.
It has been pointed that there will be activity on 2012, electromagnetic solar waves to be more specific, these happen all the time though the ones in 2012 will be slightly stronger and even though these strong ones have happened before around many million years ago, we as a human society have not felt one of that magnitude.
Perhaps this is the phenomenon that many saw, specially the Mayas considering how their astronomy skills were so advance, sadly not advanced enough to explain a solar spectrum.
So in short, the world will not end in 2012 according to the trustworthy scientific community, BUT what we could end up having instead is one huge EMP that will toast a huge part of the world's electronics, heck! Even the internet could be down! WORLDWIDE! Now isn't that the end of the World!? NO INTERNET FOR MONTHS!?