One way you could improve this is by just layering all of the photos atop each other as a big PSD or the like, with the lower-resolution images scaled up and all the layers aligned and so on (with a bit of blending to make the edges less visible). Then you could just smoothly zoom from the top level down into the finest detail with a single motion path. Maybe also fade the layers in as you get closer to them like MIPmaps to cut down on artifacting.
Thanks! I tried to do this in Photoshop, but the main problem is that the final image is 1000 times smaller on an edge than the starting image. Stacking them in one continuous PSD is quite tricky. I was able to use the auto-align feature to handle bunches of 5 images at a time, but doing the whole stack seemed impossible.