No, I hadn't noticed the Hyde book buried in the FTDI site. Thanks! Combined with your book, I should be off to a good start.
My immediate goal is to operate "half" of the VNC2 as a normal FTDI USB/Serial converter, and the other half as an SPI slave to USB Host gateway of increasingly generic nature. Probably starting with something easy like USB Flash drives, but particularly trying to allow those cheap mass-produced USB peripherals (ethernet, WLAN, Bluetooth, IRDA, Flash, etc) to be used with microcontrollers. I'm hoping the VNC2 is at least close to making that possible (why yes, I do want by 32k 8bit AVR to have a 256k/16bit peripheral! Why not?!)