Technically Nintendont is playing the GameCube games on real hardware as there is no emulation (other than controllers and memory cards). The Wii U is just a souped up Wii which is just a souped up GameCube. As far as I know,
FIX94 and the other developers have taken great pains to have the games played just like they played on the actual GameCube by putting in-app timers so the games don't run too fast minus the few games they haven't fixed yet that still run too fast.
Nintendont really put the screws to Nintendo. If hobbyist programmers can do all this,
imagine what Nintendo could have done and sold more Wii U's than any other Nintendo console ever by offering GameCube VC games.
We're going on almost 1300 pages of pure awesomeness which just shows how popular the GameCube really was.