One of the admirable things about Nintendo is that they don't jump on the new-tech bandwagon with everybody else; instead they focus on affordability, functionality, and user-friendliness. To that end, there is no reason to release a new DS, as the DS Lite is exceedingly good in all of these areas. Much like the GBA SP was for the GBA, the DS Lite was for the DS an attempt at making the system a more user-friendly and functional device more than a technologically better one.
Ultimately, even the GBA only got one functionality/user-friendliness related upgrade. The GBA Micro struck me as mostly an experiment, not an upgrade. They probably wanted to see how small they could get a portable system and still make it viable for children to play it. Which would explain why it got a pretty limited run from the start. If a new DS model does come out, I expect it will be similarly experimental, and also get a limited run, as there's no practical reason to "improve" on the DS Lite's current design.
Sky Render - Sanity is for the weak.
