I recently wrote a short column for Popular Science where I speculated about when we can expect to see HDTVs and content that deliver more than the 2,073,600 pixels of the 1080p format.
For future consumer display designs, the need to go 'beyond 1080p' is being driven primarily by passive-glasses 3D technology that enables the use of inexpensive glasses that are similar to the ones used in commercial 3D cinemas. LG Electronics and other HDTV manufacturers that use LG's LCD panels have begun shipping their 2011 models that feature passive-glasses 3D viewing, and the primary trade-off of this 3D technology compared to competitors' 3D systems that utilize active shutter glasses is that passive 3D HDTVs sacrifices half of the picture resolution of 3D Blu-ray video. For broadcast 3D formats, the resulting video detail with current passive 3D technology is, at best, 1/4 the picture resolution of the 1080p format - that's approaching the pixel detail of a standard definition viewing experience.
3D displays that utilize passive glasses need more pixels to regain this lost detail, and that's why I expect to see consumer displays with double 1080p resolution coming to market as early as 2012 and going to 4x 1080p resolution soon thereafter.
Video content that goes beyond 1080p resolution is here now in the form of some streaming YouTube clips, PC content, and commercial digital cinemas where the video is delivered in form of a box of encrypted hard drives. The HDMI 1.4 specification added support for 4K resolution (4,096 by 2,160 pixels), but don't expect 4K Blu-ray movies anytime soon. Among Blu-ray's more interesting limitations is that its maximum resolution tops out at 1080p, and it does not support expanded color gamuts (x.v.Color aka xvYCC) that some HDTVs support, nor does Blu-ray video support greater than 8-bit channels for RGB color information (DeepColor supports up to 16-bit channels). However, an increasingly popular video format known as AVCHD that is utilized in many consumer HD camcorders supports x.v.Color capture although we're still waiting for a camcorder that supports DeepColor.
Increasing the resolution of a display beyond 1080p can improve the viewing experience with today's regular 2D HD content as well. If screen resolution remains static, increasing screen sizes will result in larger, more noticeable, pixel structures. Owners of Apple's iPhone 4 can attest to the visual benefits of increasing pixel density, and for large format displays including front projection setups, more pixels filling the screen produces a more seamless image that can be appreciated at closer distances. Of course, the benefits of increased screen resolution aren't fully realized until we can provide it with content that was captured, edited, and delivered to the display at full quality - ideally in a 1:1 ratio of screen pixels and video information.