You need two doublequotes:
Code:
rtmpdump -v -r "rtmp://flash73.ustream.tv:1935/ustreamVideo/11785158" -a "ustreamVideo/11785158" -f "WIN 11,3,300,271" -W "http://static-cdn1.ustream.tv/swf/live/viewer.rsl:264.swf" -p "http://www.ustream.tv/channel/armoni-tv" -C O:1 -C NB:autoPlay:1 -C NS:rpin:rpin.01836380350861533 -C NS:shimHost:"http://static-cdn1.ustream.tv/swf/live/viewer:68.swf?vrsl=c:264&ulbr=100" -C O:0 -y "streams/live_1" -o "live_1.flv"