Time for a </sarcasm> ?
What kind of specs would be needed for a DS emulator?
It's not known because there isn't an open, optimized emulator. desumume doesn't have a dynarec, and its software graphics are inefficient. Eventually, if an optimized emulator is developed for ARM target, then we'd have a better idea of 'required specs'.
Maybe you can ask Exophase, since he wrote the phenomenal gpSP emulator. You need someone else like him to take on a project like an NDS emu for ARM.