Although the interface looks and feels a bit buggy (dude, it’s a beta!) it looks very promising.
You can download it from the programs website. The beta version will expire on 15th May 2008 but a new beta should be available before that says Ian Wood. While Mac OS X 10.5.2 and Aperture 2.1 are the recommended system requirements Aperture Assistant also works with Mac OS X 10.4 and/or Aperture 1.5.6 and above.