Dave:
The generator prep consists of a mounting base and vapor isolating shroud in the front storage compartment, an automatic electrical transfer switch in the front compartment, the start switch and monitoring controls at the lighting control panel, and associated wiring. According to what I have heard about the codes, Neutral is NOT to be bonded to ground within the trailer's standard wiring, but the neutral IS to be bonded to ground at the trailer's power source (shore pedistal or generator). Trailer mounted generators are to have the neutral bonded to ground within the generator, but this is contrary to standard code for portable generators. If you have the high-end, add-on, trailer electrical protection devices added to the trailer wiring they will cut off the power supplied to the trailer if the supply neutral is NOT bonded to the ground wiring.
I guess if you want to be completely legal with a portable generator, you would open the case and bond the neutral to ground whenever you use it with your trailer, and remove this bond when using the generator in any other way. I found a discussion on the neutral/ground bonding of portable generators on RV.net, and the (controversial) solution given there was to make a jumper plug from a power plug with a neutral-ground jumper wire in it, and plug this plug into the 2nd generator outlet when using the 1st outlet to supply the trailer.
This is the story as far as I know it. I stand ready to be corrected.