Just a curiosity, I read:

Remember that we are still waiting for NVIDIA to release the 64-bit mac cuda libraries. Until that happens, we don't have cuda support on the mac.

boinc executable is an universal binary with 3 architectures (i386, x86_64 and ppc), so if I remove the x86_64 or find a way to run the 32bit, the cuda library should be loaded, is it right?
I know that now there aren't projects that supports mac/cuda, but none of the 7 projects that I use have a 64bit binary for mac...