Future chip-sets and designs?
There are reports that the following companies are designing/developing chip-sets for use of HD Photo in-camera:
(Is this what you call something that is a bit less than a "killer app"?)
Photosynth is a new Technology Preview from Microsoft Live Labs. The process is to analyse lots of photographs of some place, including identifying camera positions, and build up a 3D model of their spatial relationship. Then to provide a searching and viewing environment which shows selected photographs, panning and zooming on request, etc. It exploits special characteristics of the hierarchical image storage of HD Photo to help the analysis, and appears to use that hierarchical image storage so that it can give a rapid initial display which then sharpens as more image data is downloaded.
This prototype application is worth trying. It is a dynamic panorama stitching product, with panning and zooming, that exploits HD Photo. (With some similarities to Zoomify). Like Photosynth, it apparently exploits special characteristics of the hierarchical image storage of HD Photo so that it can give a rapid initial display which then sharpens as more image data is downloaded. Perhaps, like Photosynth, it will be a "threatening app" that helps make HD Photo more popular.
Virtual Earth 3D (Beta)
Bill Crow says that this exploits HD Photo. ( I haven't tried it). The site says: "Virtual Earth 3D brings you another step closer to knowing “what it is like out there”. You can search, browse, and organize local information viewed in three dimensions, just the way it exists in the real world".