Im beginning to think were looking at the 2012 iMac design the wrong-way-about, functionally speaking. An obvious clue is that there is only one fan to be seen, down from three in the 2011 iMac. (No ODD, no ODD fan, of course.) This implies a marked improvement in the heat management picture. It says, in effect, that far from worrying that the cooling will be a weak spot in the design, we should wondering about what justified the fan change. This change implies that the hump in the middle of the back grew not out a desire for a dramatically thin edge, but was something needed to produce a new cooling functionality. This implies that the edges needed to be narrowed to support the new cooling functionality at the center. The 5 mm edge represents the practical limit of this change, producing a startling side-on view emphasizing the stark newness of the design. I have several posts exploring the implications of the design for convection cooling. In brief, convection fuels the movement of heated air in and out of the computer. When air is heated by the components it registers a change in its temperature/pressure complex: it rises and tends to expand when entering a larger enclosing volume, which the hump provides, progressively. Because components nearer an edge face a larger volume to the center, they will tend to flow upward and to the center. The air at the top will also tend to expand and move to the center (down and tending to the center), aided by the fan at the top left discharging at the lower center. The fan discharge near the vent grid has little effect on venting the air to the outside. It merely concentrates the hot air in the path of the convection flow triggered by the heating. The pressure differential of the air and its expansive power, input vs. output, creates the venting and maintains the intake at the bottom. I think we are looking at a design, functional at bottom, of someone capable of carrying a design inspired by form into the realm of the beautiful: a genius. My question to you is, have you found reasons to disagree? What about the mysterious black objects to the left and right? Are they merely to concentrate the convection flow more effectively?