Actually, you can turn off the SD card from within the operating system in my build (using the ExpressCard icon). This way, Windows and other operating systems can still use the SD card reader.
I just had a huge discussion about this with someone else: The point of my build is to have as much exposed to the OS as possible such that the experience of running OS X does not hamper the experience of running any other OS on the same machine. As it stands right now, with this build, the CPU package uses 1.6W idle. 0.25W, on average, belongs to the CPU cores. The CPU package DRAM uses the other 1.35W. Disabling the SD card nets you basically nothing if you do everything I stated.
This build is not the same as any other for similar models of laptops, and I would really appreciate it if people wouldn't come to try and make my build like theirs. A fair number of things in other builds simply do not apply to this one, for example:
I use dart=0 intentionally to keep vt-d on for Windows.
I'm not using a patched AppleHDA because this audio system with AppleALC has been virtually flawless, and I think the audio issue is basically gone at this point.
That said, suggestions and improvements are otherwise always welcome.
EDIT: Added some useful references to post #2.
EDIT 2: Updated the PDF with some formatting and typo fixes.