I´ve been searching this for a while, and yes, cyanogenmod (at least nightly builds) support - you might have trouble getting other customs roms.
You need 2.3.4+ and 2.6.35+ kernel with CONFIG_USB_ANDROID_ACCESSORY flag set. Instructions about xml, permissions, here (sorry, cant post full urls):
Push nexus files from here:
And upload demokit via eclipse.