One of the things that attract me from Raspberry Pi was emulation. Unfortunately,Dosbox port it's very slow in most distributions (It's said that on RISCOS works fine).
I got in touch with Patrick, developer of one of the best Nintendo DS x86 emulators, to see if it would be possible a port from a86, and this is what he said:
I am currently working on an Android port (called ax86) of my DSx86 emulator, but after I get that done I would like to at least look into porting it to Raspberry Pi as well. I believe much of the stuff I do for Android I can also use with Raspberry Pi, and I would not even need to worry about keyboard and mouse emulation, as I can use the real hardware. :-)
So, in short, yes it is possible, and I might start working on it some time in the future."
Reference: ax86 blog