Well it will be interesting to see how markets in Australasia react today, mainly Australia (NZ is to small and being mostly pessimists, and very good at talking ourselves into a recession, will probably open lower)
Selling in the US was probably as a result of traders getting nervous about how Chinese market (and Japan etc) will go... seems like people are selling shares because they're worried other people are selling shares (not necessarily because the fundamentals are dramatically worse than a month ago)