ITWire

According to NASA's (albeit very low resolution) image of the satellite's final orbit, UARS seems to have tracked up the west coast of the South Island and crossed over the country to the north of Auckland.  Beyond that it was pretty-clear sailing all the way to the Pacific coast of southern Canada.

Rumours are strong that secretive US (and possibly other) military resources were used to identify the eventual descent location.

Possible culprits include a US satellite designed to track possible hostile missile launches and Australia's own Jindalee Over-the-Horizon Radar system (on the assumption that it's abilities are somewhat beyond the published specifications).

As described in iTWire's previous article on the UARS descent there are very few remaining large satellites in orbit that could have a similar uncontrolled descent - all modern satellites are equipped for a more controlled / targeted drop zone.  However, the upcoming ROSAT descent will again have the world curling its collective toes in anticipation.