Off the top of my head, it might be relevant to face recognition, or the new real-time (?) panorama stitching, or image processing in scanning apps, or advanced paint apps (properly-smearing finger paint?), or HTML5 apps (say, Google Maps), or Garage Band, guitar amp simulators etc ...

Mostly it's stuff that people only do rarely. But the big exception is the browser -- render time is still something we worry about in desktop browsers, so I bet it'll still mean something for mobile browsers for a while.