I'm testing XP RC2 Korean version(build 2526) but it is quite troublesome because whenever I install Radeon w2k driver to use ATI DVD player 4.1, it crashes. Also other networking function is still unstable with my ADSL line.
So you had better wait for the XP driver release from ATI and try then. So I am testing with PowerDVD 3.0 DTS version.
But XP is really great because there is no S/PDIF output problem without any registry hack.It just works!!