Augmented reality stands a chance as a big market, but no one is going to be searching for "augmented reality" in the wild ... they'll be looking for the specific features that an AR application has to offer. It's a tough nut to crack, AR search metrics.
Fabrication technology (rapid prototyping, home fabbers etc.) has come farther in the last ten years than 3D, AR, and many other domainer buzzwords. Search volume for related terms is pretty weak right now, but I personally believe both in the technology and in its potential to explode as a market in the coming decade. Unfortunately in that market it's largely about brandables (Ponoko.com for example) so trying to put together domains with fab and fabber and other such terms in them is hard to justify. I would love to have gotten fab.it though ... now owned by an aluminum fab company in Italy unfortunately, so not going anywhere soon .
Frank