It would be great to see U64Emu make its way to RA someday. Formerly known as KIAME, this Windows emulator emulates Killer Instinct and Killer Instinct 2 Arcade (based on Nintendo’s Ultra-64 Hardware).
I get full speed with smooth performance in sound/gfx on a mid range XP machine, so getting it to run on other platforms could be feasible i guess. I tried running KI on the UME core within RA (android version) but it is slow with no sound.
Details about the emu can be found here: http://caesar.logiqx.com/php/emulator.php?id=u64emu