Lets say this, you get Unity Pro for free if you get a Wii U dev kit. Which also means you can publish games on Wii U. This is how that works. It's not a "plugin" as much as it is a full program. Since Wii U dev kits run around 2500 bones.. I think that's well worth it.
Besides, Unity is a "beginner" program when it comes to this stuff







