Maybe someone from apple needs to make sure that newly supported kernels work on valgrind?
Apple should probably employ someone full-time to support valgrind on OS X, just for the in-house benefits...
http://clang.llvm.org/docs/AddressSanitizer.html
It catches more stuff than valgrind, and only slows a program down to ~half normal speed.
It requires compile time instrumentation, but I'm usually ok with that.