I wonder if their choice of venue — St. Marks Square, an urban space — has to do with the limits of the technology. Trees and lanscapes must be more difficult, but so would photos taken of the same place over time, as new buildings are added. I suspect all of these challenges could be circumvented with some user-generated tweaking, though.

Photosynth certainly looks like a prime candidate for inclusion in Microsoft’s upcoming 3D virtual globe — Microsoft principal researcher Rick Szeliski is quoted in the video saying “Once we can take all the world’s photos and organize them in 3D…” That definitely carries an echo Google’s mission statement.