That exploding sound you heard earlier was your CPU being declared obsolete as news that Windows Vista not only would ship without native support for Blu-ray or HD DVD, but also not ever allow playback of commercial discs on 32-bit versions of the operating systems shot across the internet like a rocket . The reason cited by the Microsoft rep was the need for only "signed drivers" to ensure content protection. Two Microsoft insiders we're familiar with who have knowledge of HD DVD and Windows Vista, have now said that is incorrect. Chris Lanier and Amir M. have both posted this evening that this is untrue, and that the operating system will not stop your computer from playing back any high definition content. Amir stated on AVS Forum "no content owner had requested that we block HD content playback on Vista (32 bit or otherwise)", hopefully leaving the door open for the majority of PC owners. Despite their statements, no one from Microsoft has definitively stated that you will be able to play back protected discs (ICT or no ICT) on your PC, only that it is instead up to software vendors like Cyberlink and Intervideo. Restricting playback on PCs to such a small audience could be a severe blow to both of the HD formats, as early adopters are often people who also like to use the discs on their PCs for storage and playback, not to mention HTPCs. Sony has already said we won't get any playback without an HDCP-compatible graphics card, we'll soon see how much hardware the BD and HD DVD camps expect us to replace.
Read - Clarifying Windows Vista Support of Protected HD Content in 32-bit Systems - Windows Vista Team Blog
Read - Vista Will Support HD DVD Playback on 32-Bit Machines - Chris Lanier
Read - Amir M on AVS Forum
Read - Vista to support HD DVD, Blu-ray after all? - CNET
Read - We were wrong about HD playback in Vista: Microsoft - APC