Interesting, but it’s probably more cost-effective to use the “printer” to construct prefabricated house pieces, and then truck the completed pieces to the building site and assemble them, rather than truck the printing assembly around.
The thing I’m waiting for is for prefabrication or other automated assembly to actually start reducing house prices. Right now, a nice custom prefabricated costs as much if not more than a regular stick-built (and I’m not talking “Palm Harbor”; I mean built to the same standards as houses like Lennar and so on).
3D printer can build a house in 20 hours
http://www.youtube.com/watch?v=ehnzfGP6sq4
Fully-customized, modular solar house is 3D printed prefab
http://www.youtube.com/watch?v=3R1CBFBxuew
3D print your house
http://www.youtube.com/watch?v=pr3lN1nSj_0
Palm Harbor also makes modulars.