Is there a limit to how high-definition TVs can get?

Lots More Information

Alvarez, Salvador et al. "HDTV: The Engineering History." MIT. Dec. 10, 1999. (Sept. 15, 2009) http://web.mit.edu/6.933/www/HDTV.pdf
Barlow, Steven. "HDTV Past, Present and Future." Audioholics. July 23, 2009. (Sept. 15, 2009) http://www.audioholics.com/education/display-formats-technology/hdtv-past-present-and-future-part-i-history
Carnoy, David. "720p vs. 1080p HDTVs: 2009 update." CNET. March 10, 2009. (Sept. 16, 2009) http://reviews.cnet.com/720p-vs-1080p-hdtv/
CEA. "HDTV." 2009. (Sept 16, 2009) http://www.ce.org/Press/CEA_Pubs/928.asp
Gordon, Clay. "The guide to high definition video production: preparing for a widescreen world." Focal Press. 1996.
Heingartner, Douglas. "Just Like High-Definition TV, but With Higher Definition." The New York Times. June 3, 2004. (Sept. 16, 2009) http://www.nytimes.com/2004/06/03/technology/circuits/03next.html
Long, Mark. "The Long and Winding Road: The Future of High Definition Television in Asia." MLE Inc. 1999. (Aug. 14, 2009). http://mlesat.com/Articl15.html
Sugawara, Masayuki. "Research on Human Factors in Ultra-high-definition Television to determine its Specifications." NHK's Science and Technical Research Laboratories (Japan Broadcasting Corporation). October 2007. (Sept. 17, 2009) http://www.nhk.or.jp/digital/en/technical/pdf/IBC2007_08040906.pdf