What they have done is combine the old D1A and drive controller chip in to one which is now called the GC2-D3, as you can see from the photo there is a big blank space on the PCB where the controller chip used to be.

Basically long technically story short. Nintendo is releasing, in newer Wii’s, a way to combat people modding their Wii’s by combining hardware components, which people use to mod there Wii’s.