About nine years ago Malcom Gladwell wrote a book called The Tipping Point. It's all about how little problems can grow into big disasters, much like epidemics of disease. At some point a problem which at first appears to be a manageable reaches the tipping point - a point at which the entire situation gets completely out of anyone's control and a very bad outcome is virtually assured.
I think all the rescue plans and stimulus packages governments around the globe have announced can be understood in terms of the economy's tipping point. If you study the major depressions of history you find that at some point along the economic decline people loose hope in their futures. This is always noted in the popular press of the time. Once hope is lost the depression is assured because businessmen don't want to invest or hire and consumers don't want to buy. So you want to avoid reaching this sort of economic tipping point at all costs.
The primary function of all these rescue packages is to keep our economy away from that tipping point. Yes, they will have real economic effects, although people disagree a lot about the magnitude of any economic stimulus they will generate. But the real role of these rescue plans is to prevent the economy-wide pessimism about the future. For if people fall into such a pessimistic funk it will take a long time for economic recovery to set in.
So I think all the debate about whether rescues will work or not misses a much more important question. Instead we should ask whether they give people hope that we can avert disaster and climb back upon the road of economic growth. I personally think they will.