The new HD technologies include anti-user nasties like "renewability" -- the ability to remotely disable some or all of the device's features without your permission. If someone, somewhere, figures out how to use your DVD burner to make copies of Hollywood movies, they can switch off *everyone's* burner, punishing a limitless number of innocents to get at a few guilty parties.
The HD DRM systems also include gems like "selectable output control" -- wherein? some programs will refuse to be played on some devices. As you flip up and down the dial, parts of your home theater will go dark. Creepier still is "authorized domain" -- the ability to flag content so that it can only be played within a "household," where the studios get to define what is and isn't a valid living arrangement.
On top of these restrictions are the punishing "robustness" regimes that come with HD DRM systems. These are the rules manufacturers have to follow to ensure that the anti-user stuff in their devices isn't compromised. It's a requirement to add expensive armor to products that stop a device's owner from opening up her device to see what's inside, and make changes. That's bad news for open source, of course, since open source is all about being able to look at, modify and republish the code that runs a device.