My BeagleBoard-xM lives!
Granted, using the provided Angstrom distribution, but that's a good first step (and it verifies my hardware is working properly).
I've made a public gist for those interested in the output over the serial port (the DB9 style one) during boot. If you've got a BeagleBoard-xM and are using the supplied SD card image, on first boot, just know it takes forever and a day to read the ramdisk.
Oh, and in case anyone wants to order a power supply, real serial cable, plastic standoffs, and plastic screws (to get it off the table), here's the DigiKey part numbers you'll need:
Power supply (5V @ 2.6A): T988-P5P-ND
3m male to female DB9 serial cable (straight through): AE9871-ND
M3, 15mm long, hex, threaded plastic standoffs (need 4): 25512K-ND
M3, 6mm long, flat head driver, plastic screws (need 4): 29341K-ND
In all, the accessories should run about $23 (USD) plus shipping and tax. You don't need the USB OTG cable (besides, it can't supply enough juice to use the BeagleBoard-xM USB ports as a host).
Now to build my own version of Linux for it!
EDIT: Also of interest, a gist of the /etc/fstab as found inside the Angstrom distribution that comes with the BeagleBoard-xM.