Nope, after seeing the light, I'm trying to get cgminer compiled and working perfectly on OS X 10.6.8.
I've been through the CCFLAGS dance already having compiled the ArtForz cpuminer (for Litecoin mining) on this particular Mac (Mac Pro 3,1 - 8 cores, Xeons, still reasonably nippy). However I've got past the issue that is reported on these forums (i.e. compiler can't produce executable output) and am still stuck with a complaint about libcurl.
It simply could be that the libcurl that I've installed via ports isn't extensive enough and I'll need to download source and compile (and hope that the authors took OS X into account), it may be possible to hack a tweak into the configure script.
However I think cgminer will be the way forward for OS X.
I've also got a Hackintosh coming on line that is likely to have three highly overclockable Sapphire 5770s (small beer, I know, but not bad inside a case with a hot i5-2500 CPU). It's just a case of using up my remaining hardware now - additional investment is out of the question, until I have capital for FPGAs
Rethaw - regarding Apple's OpenCL implementation, it is poor on Snow Leopard, outstandingly good on a release candidate of Lion, and average-to-good in retail Lion. For ultimate performance, the trick is to get the kexts from that particular Lion release candidate (they may even work in teh ice kitteh too).
But, as always, the main reasons Macs don't make ideal GPU mining boxes are that 1. Mac high-end AMD GPUs are somewhat expensive, and 2. Profitability is all about overclocking, and OS X doesn't have API calls for overclocking the cards (or at least I've never seen any).
However, they are energy efficient, quiet for their heat output and reliable. All my dedicated miners are a self-optimised distro of Linux with homebrew monitoring tools, of course... but it wouldn't hurt for my workstation Macs to add a few hashes to the farm, would it now?