However, the 3DS is likely to be a different kind of 3D than we know of. Arstechnica.com released some good information about the 3DS including somewhat of a 'demo' of how it could work using an existing DSI.
Now comes the question, are these systems worth all the fuss? My answer is no, but a lot of you would see otherwise. I own a Nintendo DS lite and that is all I need. I've modded the heck out of it and would hesitate to replace it with a DSI and it's grotesque camera quality (seriously, early webcams have better resolution than those cameras). Using RAM carts the Nintendo DS lite really is the superior system, even though it lacks very minor interactivity, this is covered by the ability to still use the old Gameboy Advance games, or even a RAM expansion. Most RAM carts lack the ability to use the memory added to the DSI and XL, but this could change in the future.
The DSIXL is a great choice for people with minor vision problems (like me) and like to have something a bit larger and more showy. There is also more room for modding inside of the actual system, however, I would not recommend for people with little hands, (I don't recommend Burger King for those people either.)
3DS is likely the more major of the changes to the DS line. It's likely to use image tracking to move objects in the game making them appear three-dimensional. This will probably require a more powerful processor or even a graphics core. This is not likely to give you the power a PSP has, but it's Nintendo, they don't need that power. This power would give the system the ability to better process information without lagging because let's face it, even the DS lite lags (at least in Geometry Wars Galaxies).
Now for a year to year photo line of each handheld Nintendo system!
Images from:
-Fox