Something interesting, while not directly related to this topic, would be interactive mathematical widgets on wikipedia. There are a bunch of old java applets floating around for this kind of thing, and they really helped me understand concepts like 3D graphics. It would be nice if wikipedia had those.
Although the Augmented Reality part of the 3D models may be fun or interesting, its not particularly useful and may be annoying if you use it often (where did I put that marker paper again?). Seems like a direct interaction with the 3D model with your device would be more useful (they might want to at least provide that option). You lost me at print this first.
Bringing 3D to the Web and over reality would bring a new way to discover the world around us in a fun and more natural way. You + Sketchfab (<a href="http://news.ycombinator.com/item?id=4717569" rel="nofollow">http://news.ycombinator.com/item?id=4717569</a>) would be amazing.