I think US economy is fundamentally sound.  There is a healthy correction in housing prices and taming of credit markets. For investors these are good times if  you have cash in hand to invest.
In the long run stock market should rebound pretty well. I am not sure about the dollar but the decline  should be steady. The continuation of globalisation might expose the poverty in US but it is an indespensable part of any economy. The upcoming presidential nominrr will be seen as a key to future direction.