This market is going to be climbing walls of worry for a long time. Selloffs like today will follow periods of rising prices, and that's only natural.
The important thing is that the fundamentals continue to point in a positive direction: swap spreads, credit spreads, and corporate bond yields are all down significantly from their recent all-time highs; implied volatility in bond and equity options is down significantly; energy prices are down hugely; most commodity prices are up from their recent lows; and all measures of money supply are rising at a breakneck pace and stand at all-time highs.
What's more, there has been a dramatic repricing of assets. Housing prices are down everywhere, and financing costs are down as well. Equities are historically cheap no matter how you calculate it. The rewards to taking risk have almost never been so high. The vast majority of the subprime and subprime-related losses have been recognized and absorbed.
Fiscal policy is going to turn out to be far less damaging to the economy than was feared just a few months ago. Obama has changed his mind on all sorts of issues. Things could be better, but they could have been far worse. Stay optimistic, stay bullish.