Apparently the sun is destined to unleash some massive solar flares in the next few years which ties in nicely with a planetary alignment and the end of the world and such. Not that May 21st shouldn't have been the end of the world .... Oh yeah, you lost all credibility with that one!
Basically a solar flare is a huge burst of electromagnetic energy which will disrupt anything electrical and it might be so bad that systems could be down for years.
These events have been happening since time began for humans on Earth, but never in human history have whole societies been so reliant on electricity, which is the light of civilization, and been so at risk of what is a naturally occurring phenomena.
I only hope that humans in positions of power become a little less concerned about power and money and wake up to the realization that there are forces in our own solar system that we need to be aware of and prepared for.