Between manufacturing and shipping costs LCD TVs are far cheaper for electronics companies than their CRT counterparts; on top of that CRT and Rear Projection TVs have become really unpopular due to their large form factor and clunky apearance. The end result is people are willing to pay more for a LCD TV and they're less expensive to manufacture and ship so manufacturers/retailers are phasing out CRT TVs ...
Now, if you look at the surveys that have been done somewhere between 2/3 and 4/5 of all High Definition televisions are still displaying standard definition television signals (with little intention to move to High Definition) and most DVD players are hooked up to these televisions using composite cables (meaning they're not even running the DVD players in progressive scan). What this means is that people are either poorly informed on what High Definition is or have no real interest in High Definition content.
Basically, Standard Definition Televisions are disapearing because of reasons other than the popularity of high definition.
