That image could be displayed on your SDTV.

That is the same resolution DVD runs at. NOT HD.

I will make an example. 

3872×2592 http://picasaweb.google.com/kwaad2/Resolution/photo#5053862097567913314

640×480 http://picasaweb.google.com/kwaad2/Resolution/photo#5053862119042749810

Wich image looks better? (for detail)

(make sure to push the + button on the large image... for some reason it's not displaying it at full resolution still... if anyone is willing to host a ~5meg picture for me, I'll send it to you...)

Notice the text on the tabs at the top of the picture. Notice the quality on the text.

EDIT2: for some reason that website isnt displaying at 100%, but at 100% you can see each and every pixel. While at 640x480, you can barely read the text.

EDIT3: Click on download Photo, and you can see it at full size. 

 Or you could take a 1080 movie scan then downrez it to 480, and better yet take a screen cap from a game at both resolutions.

Like I said, people won't see a difference as long as you keep putting the whole picture.

Most people don't have a 40+" display with a 1920x1080 size (and running at that size) to see the difference.

You would have to take 1/4th an image that size (and doing the same with the 640x480 one) so that everyone can see the difference.

Even then, it's not sure they see the difference, it won't make a lot of sense.

You basically can't compare HD vs SD on a monitor at home. Especially since every display technology have their problems. For example, LCD have ugly screendoor effects and the worst black levels, among other things.

The fact is that Home Theater world is plagued with BS from everywhere. Few people understand what the settings are for, as they don't even always have the same meaning among manufacturers (like contrast).

The KDS from Sony are the best displays at these levels of price, blowing away most plasmas and every LCD, but that's once it's well set (actually, it destroys all LCD even when not well set). The default settings are ugly, but apparently, they do that because that's what people want (but they want that for no more that 10 minutes, they eyes and their brain won't stand it for long).

The chip on this SXRD display is so good, that it's better than most DVD upscaling players out there, that will do a far poorer job upscaling and deinterlacing DVDs.

LCD sell like hot cakes, but they are the poorest quality of HD displays. There are lots of talk of 1080p, but no content comes at 1080p, except for games, and I'm not even sure of that. I'm talking the source there, not what's out of your HDMI cable. A lot of people don't see a difference between 720p and 1080i because of all this nonsense. And they're right, there's no difference, the 1080i should even be worse, given our compression algorithms.

People that play games buy plasmas (!!!). It's actually as much a nonsense as the rest. But yes, the plasma will be burned by the games, that's the worst display to buy to play games (despite being one of the best quality), unless you can afford to buy a new one regularly.

In stores, you often see HD displays that don't even are at the right ratio !! 

When I started getting interested in HD, I couldn't understand one thing of it, and yet, I'm used to complicated stuff. Now that I know more, I understand why : this is a big mess, where they sell lots of nonsense to people, that don't understand any of it. People think the image is better, just because it's really bright ! I hear that everytime !

People basically buy HD, not because of HD, but because the screen is flat. That's why you can see a rear projection TV using SXRD blowing away the quality of even most plasma TV around it, and people still buy the plasma (and LCD), for twice the price or more, to add insult to injury. But the plasma is thinner and you can put it on a wall !

That's why I don't think most people buy HD for what it's for : quality. They buy HD for other reasons, and I can't blame them, as it's worse than gaming : only people knowledgeable enough can make an informed purchase in this field, and they are a few. Displays in stores, which are nearly always badly configured by default (to blow away the passersby's eyes) unless a fan configured them, aren't even a good mean to gauge them.

I only decided that perhaps I should leave my old SD rear projection behind, when I saw this very specific display was the only one at an affordable price, that could make SD look better than on my old SD set, despite having worse black levels (but everything else is better, and it upsamples everything to 1080p). 

who cares LCD technology is getting so good it isn't gonna matter too much if its SD or HD. I was in a shop the other day looking at LCD panels, a huge 50inch was playing starwars on SD it looked amazing.

What i am saying is seeing this new tv and its new panel with a 6000:1 contrast ratio was so much better then when lcds first come out when things looked pixelated and blocky on them.

Granted for games HD is a benefit but for real life movies when there is action all the time and things are moving you won't really notice.