Throughout history there have been hundreds if not thousands of predictions for the end of the world, yet it hasn't happened. Everyone knows the silly 2012 Mayan doomsday assumption. There are so many doomsday's throughout history, is it not surprising that people still fall for this stuff? Perfectly (otherwise) sane people are looking to 2012 as some sort of end game. This is truly ridiculous.
I, for one, think that the world will not end in some blinding flash. If man disappears it is vastly more likely to our own stupidity than anything else. This itself though, I equally find very unlikely. It is against our nature to kill ourselves. Nuclear warfare? It probably won't happen. And if it does, it probably won't be on a level that will kill end the species..
I think that we will continue on in one form or another. Considering how far we have come in the past hundred and fifty years, and considering the pattern of technological advancement we have undergone during that period, I'm not sure that we will recognize what we will be if we indeed were able to see it. No doubt, however, we will progress in either the short or long run. The issues of overcrowding, corruption, greed, and so on that we see as pains for the mid-term future will not impact us as a species. While these issues may impact some of us or most of us, they will not consume all of us in such a way that will inhibit progress in the next 100 years into the next 1000. Of this, I am certain. Man expects as a species a certain level of progress, with the general diversity of thought in the world, we would be hard-pressed to find any number of causes that together could end progress or halt advancement never mind a single issue.