Zodttd, the developer who brought us GBA4iPhone, has announced plans to release a N64 emulator for the device. But does the 3GS have enough power? Maybe.
The dev says that only the iPhone 3GS and latest iPod touch have the CPU, GPU and OpenGL ES 2.0 support to possibly handle smooth N64 emulation. But the "top-notch" N64 games might not be available "just yet."
Of course, the even bigger hurdle is a reasonable enough control scheme to make the games remotely playable to begin with. I had enough problems with the real N64 controller, so it's tough to imagine the iPhone handling things with any greater success. [All Tech Related via Maxconsole]