While it was not an easy change in itself, it also required a lot of modifications to core components of the emulator to be implemented properly (for example asynchronous IPC HLE) and a lot of debugging.
More than two years ago, Matthew Parlane and Shawn Hoffman started working on emulating the Wii Wi-Fi networking API in order to run Wii online multiplayer games inside Dolphin. This is a feature that has been coming for a long time. Beta support for the Wii official online multiplayer.
Dolphin Emulator 4.0, the newest major release of the most compatible & performant GameCube and Wii Emulator comes with about 2500 changes.
