152 inch Panasonic 4k TV
Harrods in London is offering the 152 inch Panasonic plasma for $1Million and it has 4k x 2K resolution, which basically makes it an enormous Retina display. Actually, ironically, the New iPad has 2K x 1.5k, and it cost $499. Essentially if you put 3 new iPad's side by side by side, you would end up with the same resolution as this behemoth.
The other challenge is that there is no source material that can drive this display, and no commercial computer graphics card for a Mac or PC that can drive this thing, but I just look at this thing and think about what you could do if you hooked up a Mac Mini Media Center to it. Video walls, here we come!!!