As I understand it, the only thing the Bible guarantees is this: "But of that day and hour no one knows, not even the angels of the heaven, nor the son, but the Father alone." - Matthew 24:36.
It's very sad that the picture a lot of people have of Christianity is paranoia, worry, "conspiracy theory," and all of that other junk. At times like this we need to grow in our knowledge of God and His word because although the end of the world may not happen on October 21st, it will happen soon and there are still many people who are unsaved in the world. We should also be finding comfort in the fact that we'll be meeting our Lord very soon. It's important that we are able to answer people's questions about why these earthquakes, tornadoes, floods, wars, etc. are all piling up. I'm getting very excited though! The end of the world means I get to meet my God soon, and that's a fantastic truth that gives me peace.
Whenever I hear about all of this, I can't help but sing "it's the end of the world as we know, and I feel fine..." in my head.