There are some 2160p flat-panel displays, (Samsung and others had them at CES). I believe the current HDMI 1.3 specification has a maximum resolution of 1600p (at 24 bits/pixel). As standards for higher bandwidth connectivity are developed, I am sure the industry will insist on an improved authentication/protection standard (since HDCP has already been cracked).
Here is a handy list of video standards with their corresonding resolutions, etc: http://en.wikipedia.org/wiki/List_of...ision.2Fmovies
You can see that Sony 4K is one of a number of competing 4K standards. You can also see that the total number of pixels increases exponentially with the resolution, as does the computational requirements to display those resolutions. I agree with Ken it will be quite a while before these resolutions make it to the consumer market.