We saw some rumors circulating of a redesigned 3DS that could have debuted at E3, but Nintendo's press briefing came and went without a peep of any such thing. According to producer Shigeru Miyamoto, Nintendo is focusing on its next handheld instead of considering another 3DS.
"I really feel like I'm satisfied with the 3DS hardware as it is. I feel like it's the best for this generation," Miyamoto told IGN. "What we're thinking about right now is probably going to be for a future generation of handheld." He also said that the gyroscope could serve as a substitute for the second stick.
It doesn't come as much of a surprise that Nintendo is already thinking ahead to the next generation--most hardware manufacturers constantly have future ideas in development. But Miyamoto's response seems like a fairly definitive answer to the question of 3DS hardware revisions, at least for the time being.