This is video from CES 2012. Panasonic was showing a crazy 20" panel thats displaying 4K. NHK provided the eye candy video witch was shot on there 8K Ultra HD video camera. Then  down converted to 4K.

My fist had impression I could not stop looking it looks sooooo good.
I asked if I could buy one at the show.(no luck) :-(
Then we talked about what it could be used for.
When I told them would be nice if apple had a 4K display.
They had that we are working with them on that reaction.
Sounds good to me take my money now I want it NOW! HAHA

I am going to rant about what I see out there.
Cnet tells we don't need 4K and talking about the eyes can't see and all that crap.
Well I see the need and the want even if its smaller.
Seeing 55",60",74",75",85" and so on for the big size.
They all are amazing and even down to the 55" still see the difference.
Even seeing the 20" I could see huge difference. And no I did not need to get up close to see this.
But getting up close did show how fine the pixels are. You can't see them.
Any way I think theres some thing wrong with Cnet and some of people there have lost my respect.
But then could be a marketing scheme. Talk bad about some thing people want to know more and then will check it out.
I don't think it is tho.
One interesting thing tho was at CES 2012 that was most people there asked about 4k and wanted to see it. Around the 8K sharp display all ways had a crazy amount of people loving it and raving about it.

This is the video of the 8K Sharp at CES 2012. It was shot with my 1080p sony $1k camera.
Sorry that you can't get the full effect but I hope you get to see 4K or 8K video asap.