Lots of talk lately about Nintendo scrambling to release a rebadged 3DS with less emphasis on the 3D aspects among other things. Validity of the these claims notwithstanding, it'd make a somewhat decent way to work around the lacklustre quality of the visuals that the 3DS can output, seeing as current 3DS games are designed around the severe drop in quality by rendering two viewpoints at once. This leaves the graphics hamstrung even in 2D mode, because you can't just suddenly make the characters more detailed and the textures sharper and clearer the minute you turn down the 3D slider.
It would be one way to help the poor battery life, too - and seeing as 3D is not actually a gameplay changing experience it doesn't hamper games to not run in 3D.
Unfortunately, the process of manufacturing the necessary 3D screen also resulted in the system having an extremely poor resolution in comparison to anything else on the market, and that probably has just a great effect on how the games look at this level - you can push as many polygons and pixel shaders on screen as you like but it won't help when you're displaying a screen resolution similar to most N64 and Playstation games. I think this is something that will become much more apparent once the Playstation Vita hits, but it's still noticeable when you look at the current line-up of smartphone devices.
For comparison, the 3DS's top screen (400 x 240 pixels) has half the resolution of high-end Android smartphones (800 x 480 pixels) and less than half the resolution of the iPhone 4 or the Playstation Vita (960 x 544 pixels).
I think Nintendo have stumbled very badly this time around, and unless they can really push the new price-drop 3DS (and actually make people aware that this is a new system entirely) with popular games that will sell the system, they're going to face their greatest competition yet in both the smart phone market and Sony's Playstation Vita - Sony learned from their mistakes that the PSP took too long to have worthwhile games and seems to be trying to launch with both titles that people are anticipating and a similar emphasis on social / online functionality like the big consoles and smartphones can provide.