I'm sorry. I spent about 10 hours trying to get this working. I'm trying to install the latest version of Cyanogenmod on the Nook Color. After factory reset, it says it's 1.4.3, and I was able to root (not sure if really rooted) something from YouTube, which allows me to use a different Home Launcher and Market, but that's about it.
My attempts to recovery boot using the SD anything larger than 70 MB have failed for some reason, so I can't install CM.