Right. Seeing as it's being released today, here's some emulators to test. Bear in mind they are all in
alpha stages - gameyob is
amazing on the DS, but the 3DS version still has a way to go.
None of these emulators currently support sound and have low compatibility due to the limitations of the Gateway flashcard's homebrew support. This will all change shortly, as now the coders can move development to smealum's hack which offers full access for homebrew.
GameYob (Gameboy/Color)
BlargSNES
3DNES