I have made no secret of my opinion that DRM does nothing to limit illegal copying. Non-circumvention and usability are incompatible goals. What DRM does is seriously inconvenience users. The nefarious can get around whatever is there, and the honest user gets their use of the product compromised.
The copy protection on Blu Ray and HD-DVD, AACS, is the most restrictive DRM to date, and not surprisingly is starting to show the inherent compromise between protection and usability. One of the sneaky little things in AACS is the hardware specific key, if a particular piece of hardware loses its ‘certification’ as a trusted source, it can be disabled by the key update that happens every time you insert a new disk. So lets say you have an ACME brand HD-DVD5000, and it gets found to have a bug that is letting hackers use it to break codes on disks, the AACS Licensing Administrator can update the decryption keys. Anyone with an ACME 5000 who uses one of these updated discs will find their drive bricked.
Even if this is never used the presence of the code opens the door for flaky behavior which shows the fight between convenience and protection. Two Blu-ray titles have reported playback problems. On certain players they will play badly, or not play at all. This fault is due to the DRM and the solution is likely to be a firmware update for the affected players. When was the last time you had to upgrade your DVD player firmware to play the latest NetFlix delivery?
I will continue to vote with my money, and stay out of this market all together. I predict that the restrictive, complicated, expensive and flaky implementations of HD video will open the gate for a 3rd player.