An update to our earlier post, it turns out the 32-bit version of Windows Vista can play next-gen protected high definition content. Microsoft reps said Senior Program Manager Steve Riley was mistaken when he told a group of Australian developers that Vista couldn't handle the high definition movies.
But the Microsoft representatives said the support will come from third party HD DVD/Blu-ray movie playback software developers like CyberLink who already make DVD playback software. It's up to these developers to determine whether the environment they have set up will meet the environment criteria the "content owners" impose on manufacturers. So that probably no next-gen playback for Vista out of the box.