Since I am on 4.1.0, I would like to see working versions of the RetroArch cores, but those would likely get released after Atmosphere.
In the meantime, until that happens, I'm hoping for working NES, SNES, Atari Lynx, Sega 32X/CD (although PFBA may or may not support that one) and PSX emulators on 4.x/5.x.
I would also like to see N64, Sega Saturn, Virtual Boy, WonderSwan, Dreamcast?, and GameCube. However, I don't see Wii emulation on the Switch could happen in the near future as it wouldn't be as 100% compatible as older consoles. We know the Switch has a limit to how powerful it is, even when it's more powerful than the Wii U and perhaps even the PS3.
Also, a version of Hekate that supports sleep mode would save a lot of pain and anguish.