Me and the wife did it 2 years ago from MN. Gas was sparse in some places and a lot of nothing to see until you get to some of the resort towns. If you have a duel purpose bike you can get to some of the beaches down the dirt roads but we passed them up with the GW.
The Mexican drivers are very dangerous as there are no real speed limits due to not many police around. Road very from OK to having big pot holes in them so you must watch out. Do not drive at night unless you have to, lots of animals free ranging across the roads...
Had some military check points looking for drugs not problems young boys but friendly.
Other then then felt safe and sound we do not speak but a couple of Spanish words and we had no problem getting what we need. Not many hotels on the first 400 miles a few in the towns after that one was fantastic just do not remember the town.
I have been there several times. I stay in a biker friendly hotel in the downtown area. Kept my bike in the courtyard of the hotel. Rate was cheap about 15 us money for 2 per night, but I don't think unless things have change you can get a Wing in the courtyard. Are you riding your Wing? I know the post master in that town and he also owns a small pizza joint downtown. If you speak spanish check in with him when you hit town. He can be your best friend while there. I guess you have been into Mexico before ? IF not do your home work, lots to understand before crossing.
You will need to purchase Mexican Insurance. I usually purchase it at the border. Remember, you will need a current passport now to get back across the border. You might want to check this out, I have heard both ways on the passport. Our postmaster told us that we would definately need one after January 1, 2007, but on the news a couple of nights ago they said something different. I just caught the end of it and I am not sure of what they said. We have been down there in February and it is fantastic.