those bear no comparison to the digital cameras being used by George Lucas, et al. They are wildly more complicated, etc. They aren't using them just for the sake of using them. It allows greater ease and leeway in digital editing. That being said, I think they look like crap, which I wouldn't have expected. I thought, for example, that Attack of the Clones looked horrendous, expecially in the backgrounds (in addition to being an awful movie). This may be more due to how Lucas was using them, though. I'd expect digital cameras, generally, to look as good as film cameras. They're not limited to 1040x2048 or whatever digital projection is; their resolution is close to being film-grain small.

Lucas shot with HD cameras onto either D5 or D6 tape, which is still HD res -- 1920x1080. What allows you to do this is that when you scan a full-ap film frame at 2k, the standard projected area of that is covered (but just barely) by a rectangle of pixels the dimensions of HD. If you're 100% certain of your framing, you only need to scan the "HD" area of a film frame. When recording, you plunk it back in the right spot, and you'd never know the difference, since the black areas between frames are masked during projection anyway. This technique was used extensively on Jason-X.

For a good discussion on the benefits of shooting on HD, see this SMPTE/New England article. Obviously, the article is pro-HD and makes no mention of the downsides to shooting HD, but it brings up some valid points. The downside is when you read things like this:

The producer of the film went on record to state that they were able to safely blow up their HD images by a factor of 100% for special effects as opposed to the 15-17% they had been limited to in film.

That, IMHO, is one of the reasons things look like crap in some cases. Instead of scanning a full-ap film frame to do something like a pan-and-scan, they end up scaling up an HD res frame to twice the size, and coping with all the attending problems.