The other thing I don't think people understand about the current crisis (it's lost in the noise over where to spend the stimulus/TARP funds and philosophical debates over nationalism/Keynes, etc.), is the role of excess debt.
If you look at it from the perspective of debt, this is a crisis more about solvency than sentiment/liquidity. Here's why. The amount of debt that is currently held in public and private hands (corporate and consumers) is estimated to be 350% of GDP (there are multiple estimates in the same range. Here's a good chart of debt growth and an interesting discussion).
Historically, it appears that sustainable debt levels are approximately 150% of GDP (there has been lots written that Greenspan's "Great Moderation" fundamentally changed that ratio, although I think those arguments are now deprecated). So, the current situation looks like this:
A good assumption is that $20 + trillion in excess US debt (200% of GDP), mostly in private hands, must be wrung out of the system before it stabilizes. Consumers and corporations appear to agree. Once the vulnerability posed by this excessive debt was exposed by explosions in the shadow banking system, both consumers and corporations began to radically reduce spending to pay off debt in an attempt return to solvency. This is likely, given the magnitude of the debt involved, a fundamental change in behavior that spells the end of the consumer (and the arrival of something else) economy.
NOTE: This pay-off period may take decades (much of it through write-offs, defaults, or inflation). IN the meantime, declining asset values and economic depression will be the norm (as in, the new cars stacking up on these docks will end up as scrap/parts/auction sales).
NOTE2: Stimulus won't accelerate payback of this debt since it only adds more debt. Also, this is a behavior change borne out of balance sheet insolvency and not merely sentiment (which can be impacted by stimulus).