Is Apple TV's (and Xbox Live and VOD's) HD truly high definition?

HD is coming in a lot of forms these days, but ZDNet's George Ou thinks some of them -- like Apple TV, Xbox Live Marketplace, ABC.com streaming and cable VOD -- don't count. Sure all of these sources are HD resolution, but George's argument is that due to overcompression and low bitrates, they don't compare with 1080p upconverted SD DVDs, much less Blu-ray or HD DVD. Low bitrates might mean less detail than we're used to and some issues with fast moving action, but we've checked out all of the above, and if you've got the pixels, then you're HD. Whether or not thats enough to satisfy is up to the viewer, but we're sure there's a faction out there arguing if you have to get off your couch to buy it, it's not really a high def experience either.