The Star Trek : TOS set on HD DVD has gotten outstanding reviews for both the picture and the (upgraded) sound - even the ‘cheesy’ effects appear much better in HD. The set is actually manufactured on combination disks that contain both standard DVD and HD DVD versions, so those with regular DVD players can still enjoy it, while being future-proofed if/when they move up to an HD DVD player.
I think that HD in general is poised for mass consumer breakthrough - more and more people will be buying new HD-capable TVs, spurred by the impending switchover to digital broadcasting and the increasing number of HD channels. Those same people will hike the demand for HD DVDs because their expectations of quality will be raised...and regular DVDs, even upscaled, just won’t cut it anymore.
Where are some of those outstanding reviews you are talking about?