I use TinEye a lot and I think this will be great. My typical uses of TinEye, that will probably be improved with the bigger stock:
- somebody put text over a nice image and I want the unmodified version
- searching for bigger, better quality versions of an image (e.g. wallpapers)
- finding other images from the same author/gallery (since it links to the sites that hosts the copies)
- finding the name of the movie, person or object pictured (because copies will be hosted with different, probably meaningful names and in pages with subtitles)
- somebody put text over a nice image and I want the unmodified version
- searching for bigger, better quality versions of an image (e.g. wallpapers)
- finding other images from the same author/gallery (since it links to the sites that hosts the copies)
- finding the name of the movie, person or object pictured (because copies will be hosted with different, probably meaningful names and in pages with subtitles)