The consensus is that the HD-DVD discs look amazing and have used the VC-1 codec. But Bluray have opted to use that old MPEG2 codec and they just don't look as good. Bluray have been shooting their mouth off for years now about how much better they will be and they haven't delivered. Meanwhile HD-DVD has become the enthusiasts choice and people have even figured out how to author their own HD-DVD discs playable back on the machine.
HD-DVD hardware is half the price of Bluray hardware too. Consumers will vote with their wallets here.