Here's something practical, especially for businesses or even bars. Planar's new LED-backlit UR8450-MX 84" UHD display can show four different 1080p signals (up to 10-bit @ 60 Hz max) in a tiled fashion. This is the first major manufacturer to offer such a technology natively built in. There is 3rd party hardware capable of doing 4x4 tiling on a UHD display, but it's maxed out at 960x540 per signal, and then each is upscaled to 1080p. We all know that a decent amount of 2160p content is still far off, so a feature like this can give these UHD displays something to do until the real content actually arrives.
These displays are being targeted for business, hospitals, and other specialty uses, with a price tag to match ($24,900), but I do hope that a feature like this will be made available down the road on future consumer-grade 2160p displays. This would be a cool feature to have for NFL ticket or March Madness. Most displays that offer PiP typically only allow the other video stream to be displayed at a very small size with far too little resolution to discern much of what's going on in the picture.
Edited by Seegs108 - 5/30/13 at 1:07pm