Elop has gone on record claiming that the Lumia 800 is a "refinement" of the N9. That's not a good use of English and we can't let it slide, because every hardware difference between the two devices leaves the Lumia 800 worse off. There's no globetrotting pentaband 3G, which means no AWS support for T-Mo USA's network. The front-facing camera and notification LED have evaporated. The screen is slightly smaller due to the intrusion of the Windows Phone buttons. There's only 512MB of RAM instead of 1GB. Onboard storage maxes out at 16GB rather than 64GB with the N9. NFC is also inexplicably lacking, so the phone can't pair up with Nokia accessories and it probably won't be able to keep up future innovations that Nokia says its working on for Windows Phone 8 (aka Apollo).
On the other hand, many of the best features of the N9 have made it through. The machined polycarbonate shell radiates precisely the same industrial style, while simultaneously giggling in the face of scratches. The convex Gorilla Glass screen flaunts some of the best workmanship we've ever seen on a mobile device and it fits so perfectly that barely a speck of dust can get caught in its frame. The proximity and light sensors are neatly hidden behind the glass, leaving the front face of the phone almost entirely undisturbed, except for the earpiece, Nokia logo and Windows Phone symbols.