Nintendo may be in deep doodoo if this turns to be true. According to the Wii Key team, they say that they have breached the Wii U. So that means that pirates will now be able to run backup of games. This doesn't seem to bring much to the table on the homebrew scene.
Nintendo is actually aware of the situation, their response to EuroGamer
"Nintendo is aware that a hacking group claims to have compromised Wii U security. However, we have no reports of illegal Wii U games nor unauthorized applications playable on the system while in Wii U mode. Nintendo continuously monitors all threats to its products' security and will use technology and will take the necessary legal steps to prevent the facilitation of piracy."
If this is true, the Wii U has been cracked just as fast the Wii. The theory that Wii U is using Wii hardware just a bit more efficient seems a bit more plausible now.