Calculated Risk points to this piece in The New York Times about the increased savings rate:

This shift back to thrift may seem to be a healthy change for a consumer class known for spending more than it earns, but there is a downside: American businesses have become so dependent on consumer spending that any pullback sends ripples through the economy.

This is a common observation; the American consumer may now reset to a higher level of savings and lower level of consumption, which will cause problems for the sectors of the economy driven by exuberant consumption. What I don't get is this: didn't everyone assume that debt-driven consumption would eventually have to abate? I have read arguments to the effect that the massive influx of capital due to the aging of Japan and the rise of a Chinese savings class enabled the American consumption binge, but that can only go so far for so long.

You can't consume more than you produce over the long term, so it seems moot and irrelevant that the American economy has become dependent on this dynamic in the short term. It isn't a downside generated by a choice between alternatives, it's simply a structural inevitability of how the world works that American business can't always depend on increasing levels of consumer debt to drive demand.