Update: Adrian has done a Reddit AMA. It's definitely worth reading to get insight into his process for building the Serenity. He's also selling a micro-scale Serenity kit on Bricklink.
That's right, it's 7-feet long, weighs 135 pounds, and took 475 hours to build. In addition to the gorgeous exterior, the interior of the Serenity is also built to minifig scale. Adrian modeled everything from the cargo hold to the dining room inside Serenity, using the Quantum Mechanix blueprints as his guide. You really have to check out his Flickr gallery to appreciate the level of detail that went into this amazing LEGO MOC. (h/t to Io9)