Image quality of upscaled 1080i image vs. native 1080i image (1 Viewer)

Sorry if this is answered in detail elsewhere, but with all the talk regarding the Liteon LVD-2001 DVD player (for those who haven't heard, its biggest feature is the ability to upscale from 480i to 1080i, among other resolutions, via component output)--how does the picture quality of an image upscaled from 480i (e.g., typical DVD movies) to 1080i compare to the PQ of a native 1080i image (i.e., one that hasn't been upscaled--assuming that there is such a thing)? Or let me rephrase my question to be a bit more specific--objectively speaking, how much of a difference is it?

On a related note--what is the sorting order, from lowest PQ to highest PQ, of the following resolution types:

480i, anamorphic (are all 480p considered anamorphic and vice-versa, as far as DVD movies are concerned?) 480p, native (i.e., unscaled) 720p, native 1080i, 480i upscaled to 480p (can this even be possible/allowable?), 480p upscaled to 1080i (assuming that this is also possible/allowable), 480i upscaled to 1080i (possible w/ Liteon 2001 and Samsung HD931)

Yes I know that judging picture quality can be quite subjective depending on the source and viewing equipment, but I'm more interested in the resolution numbers themselves.

Also, are the terms "upconvert" and "upscale" interchangeable when it comes to resolutions, e.g., 480i upconvert/upscale to 1080i?

Thanks!

You can't ADD any video detail by video processing. So material that takes full advantage of 720p/1080i will look much better than processed video taken up to that same level. You can see this with processed DVD versus Hi-Def very clearly. While the processed video will look (or should if the processing/scaling is worth anything) much better than the original, there is only so much that can be done. Over the air TV can be processed all the way up to as high as you want, maybe 1080p even, but it will still look like crap compared to a full 1080p video feed.