Here's some unfortunate news for early HDTV adopters. It looks like late changes in the Advanced Access Content System (AACS) will cause a downgrade in picture quality when the signal is sent through analogue connections.
In a deal reached this week after tense negotiations, the eight-company consortium behind the Advanced Access Content System, created for use by both high-def formats to prevent unauthorized copying, has agreed to require hardware makers to bar some high-def signals from being sent from players to displays over analog connections, sources said.

Instead, the affected analog signal must be "down-converted" from the full 1920x1080 lines of resolution the players are capable of outputting to 960x540 lines—a resolution closer to standard DVDs than to high-def. Standard DVDs are typically encoded at 720 horizontal by 480 vertical lines of resolution.
It's hard to say at this point just how many people will be affected, but I think it's fair to say that many current HDTV owners will not be happy with this news. For more information, the whole article can be found here.