If you have a R4 for your 3DS or DSlite/i you can just emulate snes games on it

if the snes version doesnt come out on the eshop
No offense but most Snes emulators on the DS mode aren't that great. in fact, most of them suck pretty badly due to the DS's weak CPU
Should be able too, but N doesnt seem like they really care about bringing SNES or GBA to the 3DS unless you have an ambassador 3DS.
I'm sure the 3DS can handle them just fine like you said, but it'll be a cold day in hell before Nintendo writes an emulator for Snes games, at least, for non-Ambassador 3DS owners. If there are ever unofficial emulators, let's hope they're not as buggy as the ones on the PSP
And out of curiosity, why do people want the GBA version over the Snes version? The Snes version had far superior audio quality, but did the GBA port have any extra content?