Generally speaking, the use economy gets very volatile everytime the USA picks a new leader.
It usually gets better going into the new leader's second year, after taking office. But I doubt it will get better fast, since many factors usually stay relatively constant instead of the way they are now.
This has nothing to do with the statment of eliminating Bush tax cuts. A small increase in taxes isn't near as bad as loss of purchasing power by allowing capital to remain nearly idle in a bank account(idle for the owner of the cash, not idle for the bank).
The fall in the markets are do to the economic reports that are doing far worse than predicted. Everytime one drops, it is far more job losses, far worse retail sales, and far worse factory orders than expected.
Banks are still failing, and credit is still not flowing well again.
But whether it will get better or worse is anyone's guess with such interlinked economies, anyone of them doing the wrong thing can end up draging the others down just like bank failures are doing do to banks with them linked together so tightly with investment portfolios.
If other countries decide to ditch the USD and peg their currency to the euro, the US economy will get far far worse.
Protectionist methods will only be better for America, but far worse for the rich elitists who are taking advantage of the cheap labor all around the world.
We will probably see that a huge public works system is needed if the world insists on creating jobs everywhere but America.