Some of us actually use our computers in the family room, instead of spending all our time in a dark basement staring into the screen all night long.
This is nonsensical. While I understand it's advantageous not to have a box and cabling to deal with, once you get the imac to it's current size, it is plenty compact to put in a family room or anywhere else you want to use it.
Why would you sacrifice any functionality (not to manage get added heat issues) to save an inch or two at that point?
Seems some of you are more concerned about showing your imac off as a decoration than actually using it.