JVC has put together something that could be considered rather ridiculous. An 8K projector - the D-ILA 3 (RGB). It runs at a resolution of 8192 x 4320, while the highest resolution that most consumers have access to - 1080p - is just 1440 pixels wide.
8K content is pretty much impossible to find. You'd have to use some of the highest resolution still cameras available to take shots and string them together like a stop-motion film. Even then, you'd need a ridiculously high-spec computer to play the files back without stuttering.
Luckily, the projector also supports 4K playback - a standard which is more widely used by high-definition cinema cameras. Even so, one full-aperture 4K shot contains 12,746,752 pixels.
The projector pushes out 10,000 lumens of brightness and has a 5500:1 contrast ratio. There doesn't seem to be a price attached, but the 4K camera that JVC is announcing alongside this product costs "under $200,000". You'd therefore expect the price-point of the 8K projector to be similar.