a design i'd find interesting(made it with colors!DS)
image 1: casual mode.
for full touch games, and media playback.
what you can't see is the camera on the back, didn't bother drawing that.
imaging it's pretty much on the backside on the same spot as CAM1
image 2: action mode.
for 3D racing, fighting, and other action games played best on a nice big high-res screen.
this mode reveals the ABXY, start, select, and D-pad buttons as well as an analog stick(2nd one could be added on the opposite side near ABXY)
image 3: dual mode.
this mode is required for DS games, and offers 2 sections on 1 screen with a skin-able border in between(3DS games could come with their own border)
this mode hides the analog stick, but offers easier access to the touchscreen.
this design uses 1 gamecard slot compatible with DS and 3DS gamecards, as well as 1 SDHC memorycard slot for cards of up to 32GB.
i decided to place the 3.5mm audio port between the shoulder buttons, next to the gamecard slot, because i hate how on the DS/PSP the 3.5mm plug is always where i want my hand.
the volume buttons are on the screen section, so they don't get in the way or accidentally pressed while mashing some buttons.
4 speakers, 1 in each corner of the screen section. this is to simulate some basic surround sound and to overcome the problem of loss of stereo effect when rotating the screen.
power button is a slider like the DSlite has.
the built-in microphone is centered below the screen(in the widescreen modes)