I don't really have any serious intentions of buying one, either - the promise of the DSiWare store seemed powerful upon its release, but has largely turned out to be a disappointment, no-one had (yet) given a convincing explanation for what cameras are doing on that thing, the price is still higher enough to be a significant factor, and it loses the GBA port from the DS Lite, something I do still enjoy having. They really didn't make the case, in my opinion, for those of us who already have and enjoy their Lites to want to upgrade.
Having said that, this video is fascinating.
Anyone who remembers Johnny Lee's Wii projects will recognize the basic elements at work here. (And you should really watch those videos if you haven't; they're great, and it's a crime that in almost two years we haven't seen much of anything come out of that.) But certainly nothing like that has been done on a handheld before that I'm aware of, and it's a reason, finally, for those cameras to exist.
According to BoingBoing, "Rittai Kakushi e Attakoreda" (Hidden 3D Image: There It Is!) is showing up in the DSiWare store in Japan this week; no news as to whether it will see a release in the U.S. I seriously hope they're localizing this or something like it, though, because this is the sort of thing that gets people excited about incremental upgrades to gaming hardware. Show us that it really can do something the previous iteration couldn't do, and then show us reasons to care.