All I can think of is ugly, stretched resolutions.
It probably won't DS games are not made for screens that big and are still in production.
yea its not gonna happen and honestly idk why anyone would want to play a ds on a home console, not to mention the resolution would be terrible.
What I pretty much described (I obviously didn't do too good a job doing it.) was downloading the sprites to your wii u, (not the game just the sprites so that you still have to hook up your ds/3ds) so that you wouldn't get the stretched screen and ugly resoluion.
Yes I doubt that nintendo did/will do that, but hey it's an idea, they have to have something planned, because the whole fact that the wii u looks like a blown up, cut in half fancier ds, doesn't seem like a coincidence to me.
Although admittedly, I know that I'm probably wrong. you guys know more about this Than I do, all I've done is an hours worth of google searching.