Hacker Mathew_Wi has managed to inject N64 games to Virtual Console on Wii U. Even though not all games are compatible according to Mathew_Wii, it is still great progress.
Virtual Console injection is possible on Wii and it was a great way to emulate older consoles till good emulators emerge. It is still a preferred way for some gamers even though emulators managed to go a long way on Wii. In 3DS scene, NES/GB/GBC/GBA Virtual Console injection is a widely preferred way as it gives nearly perfect emulation.
This N64 Virtual Console injection by Mathew_Wi has been confirmed as “not fake” and working on 5.4.0 by Wii U devs. It is always good to see the Wii U hacking scene advancing even though this won’t be released for some time.
This also more or less confirms it is still possible to use hacks on latest 5.4.0 firmware despite what we said before. I would still wait a bit more for more info about the safety of latest 5.4.0 firmware before updating if hacking your Wii U is important to you.