Nothing fancy is running yet, all they've achieved so far is a proof of concept that they've bypassed the Wii's protection with some encryption codes they swiped from the Wii's memory.
The proof-of-concept computer won't give silicon circuits any threat when it's running at just 0.15Hz and takes up as much space as a mini fridge, but the hope is to dramatically speed up and shrink down future iterations to where there are advanced computers that occupy the same size as real muscles.