Progress isn't linear. It's hard to make extrapolations given the rapid change in the world over the last 50 years or so, but we know that people can't eliminate business cycles, panics, etc.
Again, look at Japan. Bubbles happen and can be very destructive. Given the speed and ease of moving money around these days, China and (even more-so) India will hurt very quickly if their economies enter a severe downturn.
The widening gap between the rich and the rest of us is a big problem around the world. http://www.economist.com/node/21564414 - a good story(, but taxes do have a large role to play).
Watching actions is a good idea. That's why Putin shouldn't pay attention to the chattering classes over here. ;-)
Cheers,
Scott.