Engadget - Once you've cleared the $25k or so in your budget that it will take to snag one of Sony's 4K VPL-VW1000ES your next problem will be finding some 4096x2160 res content to view on it. While showing off the new beamer for its Japanese audience at CEATEC today, Sony announced the PS3 will get a firmware update around the beginning of 2012 that will allow it to natively output 4K stills.
Most fairly recent DVD movies/TV shows (720x576 in PAL rather than the 720x480 I believe is used for NTSC?) look perfectly fine on my 51" 1080p TV. Hell, it's even sharp enough for the built in 2D to 3D conversion feature to do an okay job with it.
Obviously though, even with an upscaling player a DVD movie doesn't have the potentially pristine image of a Blu-ray movie.
My netbook can display a high resolution image as well, but because of the small screen I have to scroll around to see everything.