One of our Christmas presents this year is an Oppo DV-980H DVD player. It's a featureful little DVD / DivX player from a small A/V company that's building interesting products.
One of the player's features is upconversion. It'll take an ordinary DVD and convert the output to 1080p so it looks great on your HDTV screen. But thanks to the evils of DRM, it will only do this over an HDMI cable, not standard component cables.
Video up-conversion over the component output is only available for unencrypted discs such as home video and consumer-created contents. Most commercially pressed DVD discs are CSS-encrypted and will be limited to 480i/480p resolution. This restriction applies to the component output only. The HDMI output is protected with HDCP and has no such restriction.Is your TV more than a year old and lacks HDCP support? Too bad! Been using the same component inputs for three years because you're a movie enthusiast and early HDTV adopter? Too bad!
Fortunately, the Oppo player has another neat feature, coyly referred to above as "consumer-created contents". It plays DivX and XviD AVI files; either read off of disc or through the handy USB port. And those movie files will be upconverted to 1080p on the component cables with no fussy encryption.
So in other words, if I legitimately buy a DVD I can't play it nicely on my TV. But if I steal the same DVD online and download it to my Oppo, it'll play beautifully. I love how DRM is protecting the movie industry.