I was thinking if you could add "simulated multitouch" to VGBA, much like the way lcuk's doing in liqbase. Since the touch screen seems to always return the "average" position of any two presses, I believe there should be enough precision to at least recognize, while holding A (or B), which "on-screen d-pad" direction you're touching with your other finger.

Of course this just adds a bit of extra coolness (and not much more usefulness), since you can already play mario kart with the hw keyboard

(EDIT: seems this is VGB topic. oops. either way the suggestion applies to vgb too.)