Capcom confirmed it wasn't even fully pushing the 3DS to its limit. So we can in for a treat. I expect Nintendo to push the bar with metroid if serious work is put in. The DS version was impressive.
If Capcom can polish up Monster Hunter 4, that too can look impressive. I'm holding on to future titles to do that.
3DS is only 19 months in the market, heck we'll see in some games in the next few years going leaps beyond what already has been done.
That makes me think, if a non 3D is to be game, some dev can push all the processing power use into the graphics, like push for more polygons or high quality textures instead for improved AA or smoother framerate. Some games can do AA in 3D too like Mario Kart 7.
To add, we already have games looking better than Wii game in some aspects due advance shaders and lightning techniques. Not higher polygons nor geometry, but it looks better on the smaller screen, if it was blown up then yeah you can tell the difference, but 3DS still overcomes the Wii with the modern GPU capabilities.