I keep hearing about how DS games look really ugly on the 3DS, some sort of artifacting going down or something, if 1Up's Jeremy Parish is to be believed (he posted some videos which were too low quality to make out). 
 
Has anyone posted some quality pictures of DS games on 3DS? 

I, too, am concerned about this. I've been wanting a DS for a while now but waited as 3DS = more power. However, most of the games I want to play are old DS titles.

Old DS titles will still be in 2D from what I had previously heard.

" Old DS titles will still be in 2D from what I had previously heard. "

This isn't a comparison of screenshots, but Kotaku ran a video before that seems to indicate games will actually look a tad bit better, just because the screens are better. You can also hold some buttons (I think Start and Select) to run the DS games a little smaller on the screens, making them look even better. 
 
In any case, whether the quality is actually better or worse, everything I've heard seems to indicate that it's barely an issue either way.

I remember reading somewhere that they take longer to load but they look a little better than on the DS (no widescreen though). It would suck if they didn't run as well, but I'm not trading my lite in anyway.

That sounds like a smart move, the DSi XL is totally rad!
@melcene

They're going to look like how PSOne games look when played on PSP if you stretch them. 
 
The resolution is higher on the 3DS so they can't look the same. Either they get stretched and blurred out (think watching a DVD on an HDTV)  Or they are displayed smaller on the screen at native resolution. That's a problem for stylus games because the play area is very small.