1) Housing Bubble v2.0
Even worse than the last, but the reality is that none of our bad habits have changed which caused the last housing bubble, which means history is doomed to repeat itself. When will people learn?
2) Education Crisis
The cost of education has been rising well beyond inflation for many years. This will eventually cause a crisis.
3) Health-Care Crisis
Obama's worst fears have come true where decisions that were made only accelerated the crisis's timeline and other countries lost faith in the dollar and switch to gold as the standard for international currency. The surplus of US dollars being circulated as countries spend them to get out will cause massive inflation of the US currency.
4) Government Spending Crisis
The government has spent so much money and was unable to pull back the "stimulus" without causing a massive inflation. Other countries lost faith in the dollar and switch to gold as the standard for international currency. The surplus of US dollars being circulated as countries spend them to get out will cause even more massive inflation of the US currency.
5) Financing Crisis
The lack of taking any risks will cause many companies to go bankrupt as they seek funding, but nobody is lending. This will cause many companies which would have fueled economic growth in the coming years to be non-existent causing an economic downturn.
Lots of possibles there (as well as many more that I didn't mention). I think the most interesting is #2.
For the average Joe, the key thing to remember here is the date. 2015. Be sure to sell your stocks before then and then buy them back after the collapse hits bottom.