I guess a start would be to port 1964 to Linux/MacOSX/ppc. You could then use that with Rice's Video plugin (which is open-source) and you'd have a pretty decent N64 emulator. However, the problem is that 1964 at the moment is x86 - so yeah, someone would have to do the legwork to port it to non-x86 architectures. I don't have the skills to do that.
N64 emulators are in a pretty lousy state portability-wise. That, and nearly all of them don't have the same level of accuracy and compatibility that SNES9x and bSNES have for SNES.