Economist chart.
For a long time, China's deflationary impact on prices was seen as a good thing: it meant China's rise didn't lead to more expensive goods in the West--just the opposite.
But with the West is a slump, a vicious cycle sets in: more belt-tightening means less demand, means lower prices still, means . . ..
So the view of economists rounded up online by the mag is, "deflation is the bigger short-term danger in big, rich economies, whereas inflation is an immediate worry in many emerging economies and, potentially, a longer-term danger in rich ones."