The games are never going to use GPGPU. I've never seen a game anywhere use GPGPU (maybe crappy Physx? Which is only visual effects anyway? ugh).
A GPU is for graphics in a game console. If it's doing something else you're doing it wrong. If you want to use GPGPU to encode a video on your PC faster, cool (and they're surprisingly ineffective even at that, offering only quite modest speedups over the CPU given their brute force). Other than that, no.
For Wii U games to look their best they'll just have to work around the (apparently) crap CPU. Luckily, this should be doable in time imo. You'd much rather have a crap CPU than a crap GPU for games.
Civ 5 uses DirectCompute to decompress textures, they even included a benchmark mode that a lot of sites use to rate new graphics cards on their compute power.
Just Cause 2 uses CUDA for its water and DoF effects.
There have also been plenty of OpenCL demos showing advanced lighting effects. For the most part there hasn't been a lot of in-game implementation of GPGPU APIs because the consoles haven't supported them and most PC games are based on console code. Wii U having it is good because the other two certainly will and the bare minimum baseline for games will include GPGPU support in all hardware.