From a recent survey of just over a thousand people conducted by Best Buy (which was certainly done for marketing purposes, but is still informative):
• Almost all consumers (89%) feel they don't completely understand HDTV technology-how it works and what it takes to get the full HDTV experience
• While 41% of HDTV owners admit to knowing little to nothing at all about HD, they would not want to admit that to friends and family; Half (52%) of HDTV owners agree it would be difficult to admit their HDTV wasn't set up right after showing off to friends and family
• Half of HDTV owners (50%) admit they are either not watching HD programming, or they aren't sure if they are. Of these respondents, 35% didn't realize they needed to subscribe to HD programming to watch HDTV
• Nearly four in ten consumers (39%) don't identify an HD-ready TV as a necessary component of the HD experience
• 52% of respondents don't realize you need a special HD compatible cable to experience HD programming
The fun really starts when you start trying to explain the difference between Blu-ray and HD DVD.
Anyway, do your part: make sure everyone you know with an HDTV is actually getting HD content, via their cable or satellite company, over-the-air broadcasts, or HD disc. It will make them happier and make you look smarter.
(Also, that survey quote is from an email, not the link, although the information is the same; that's why it's not a direct quote, should be looking for one.)