Hey Dave,
I know this is an old thread but finding it was somewhat timely for me.
I just completed a slideshow presentation for a local company that was spot lightng the best places to work in Rhode Island. There were about 52 companies, each with a bunch of photos, and a logo. I had our graphics department put 3 photos into a PSD template I gave them that had 2 alternate positions. I then brought the PSD files into AE as composites and animated them.
It was a long, grueling project with a tight deadline. I swore that unless I could come up a way to create a template with motion, where I could just drop in the photos I would never do it again.
the link you gave the original poster pointed to a page that explained about .aet files, but now how to set up something like I am lookng for.
Any suggestions?