I don't believe the world will end, personally. I can tell you something true and vague, though: Something big will certainly happen.
If anything, something dramatic will occur precisely because people have been expecting this date for generations. Our antsy-ness, hyperactivity, and brilliant speculation will self-fulfill with no other variables at work.
Who knows? Tomorrow you could die. I hope not. But live like it's your last day anyway—that's the cheesy lesson we should take away, up until that date.
Thanks for the question,