Alrighty, after using the excellent guide, I'm not up and running with a hacked Wii. I managed to get USB Loader working and all, and ripped my copy of Punch-Out! and was able to run it just fine off the external HD i'm using (a 320GB drive). Love the GAF symbol wiimote pointer!
I'm still getting used to all this IOS stuff, but I think I have a rudimentary handle on it, except for a few points. Have some questions:
1) I installed BootMii successfully to boot2, but I just realized that I didn't back up my NAND before hacking everything the rest of the way. Did I mess up in doing this, or is my original NAND intact still, and capable of being backed up via BootMii?
2) Apparently, the Wii isn't compatible with some SD cards, is this correct? I had been using a 16GB Kingston SDHC card and was able to run Virtual Console/WiiWare stuff that I bought just fine. Now, when I went to hack my Wii, I was able to install HBC just fine off that card, but nothing else would read off it, giving me read errors. I ended up using a 4GB microSD card I had inside an adapter.