http://www.costco.ca/nintendo-ds.html

Costco is among the sites that I've seen and still are listing 3DS with DS.

They all have Vita section separate from PSP, though.

Shouldn't Nintendo do something about this?

Yeah but then sales would slow down to the same rate as the Vita.

Nintendo should stop all 3DS shipments to this retailer until this issue is resolved. That will show them.

The Tesco & ASDAs where by I live, as I mentioned in the Vita predicted sales thread, still lump them all together.  My local GAME did too (oddly enough) until recently when they properly separated them. At least that was progress.

After watching Nintendo Direct on my 3DS last night and seeing some of the upcoming games, I'm having a hard time seeing the difference between 3DS and DS, too.

Easy. The difference is the DS was a success.

I think this is part of the reason why Nintendo totally changed the Wii U brand on the boxes to be blue + yellow ... completely different from the white/grey Wii packaging. And the Wii U hardware box is blue as well.

The DS/3DS software packaging looks way too similar.

My local Tesco has done away with DS games now, and only stocks and sells 3DS.

Ain't NA DS games in a black case?  I know european games are all white and the only game I imported from the US (The World Ends With You)  is black.

Sarcasm?  or are you referring to something else?  Because there's a clear difference in capabilities.  I've gotten myself some DS games and they look wayyyy different.