...Ben here from Gros Morne. Been following the trip, seems like you guys are having an amazing time! I'm currently in Nicaragua on the Pacific coast in a little slice of paradise called Bahia Madjuagal. Just rented a Yumbo 200 dirt bike and Ill be heading across the country to the Caribbean on a new dirt road that was supposed to have been built earlier this year (RR to follow...)
Im actually writing because I noticed you didn't get a tourist card or TVIP yet. I did this in late 2010 and rode down the Sea of Cortez side, avoiding the various checkpoints and figuring i would take care of it in La Paz. Come to find out they had changed some things and I paid a hefty fine (seems to be more the further south you go into Baja). I cant remember if it was more related to the tourist card or the TVIP, but here is a link to the thread I posted about it which includes a lot of advice, comments, and the eventual outcome ( about $100 more than I would have paid at the US border). I guess I would recommend taking care of the paperwork as soon as you can...
Also, a link to the blog I kept with pictures of the trip if you care to take a look.
Ride safe, I'll be following you guys. Hope we can meet up somewhere in South America. :-)