Hey MountainX, I think I read elsewhere that you wanted to install linux natively on your mac for performance reasons and that you were going to be doing SW dev with eclipse. Well, FWIW I'm doing exactly that and for exactly the same reasons. As you know, Eclipse can be a memory/cpu/diskio hog. I had been running Debian under VirtualBox in OSX, and now things are considerably faster.
Anyone that works with computer software is inherently and actively working around bugs in said software whether they know it or not. The fact that the open radeon driver has a bug that makes video output switch to the mini display port on certain hardware does not mean that it is impossible to run linux on that hardware. Assuming you're ok with using non-free software, the workaround is quite simple: don't exercise the buggy driver - instead bypass it by staying in text mode and installing the non-buggy proprietary driver.
You may have found another solution, but if you're interested in giving it another go, I believe you could probably get it working in a few hours if you make all the right turns at Albuquerque. I didn't, and it has sucked 3 days of my life from me. However, I learned several new things in the process, and for this I am grateful. My success was largely due to yours and others' prior work and documentation on this issue. I am just the lucky one that came along at the right time.