My current plan (which I am sure will fall apart on day 2 of the trip) is to ride to Texas (my home state) and get new tires mounted. From there I'm going to ride across the state to Big Bend and spend few days there. I spent time there in the 70s when you could walk across the river to Boquillas del Carmen and get a cold Carta Blanca. I understand that since 9/11 you can't do that anymore.
From there I'm going to cross at Eagle Pass and head for the eastern coast and eventually cross into Belize, Guatemala, Honduras, Nicaragua, Costa Rica, and winding up in Meteti, Panama. Spend a couple of days there and then head back up the Pan American Highway this time riding through El Salvador back to Mexico. In Mazatlan I will take the ferry over to Baja and ride up to San Diego (re-entering at Tecate) to visit my son that lives there. My wife will fly out and we will do some sight-seeing together for a while.
From San Diego I'm riding up to Nevada to ride Highway 50 (The Lonliest Road in America) and then over to Monument Valley. From there I think I'm going to pretty much high tail it home through the mid-west.
As I said this plan will probably fall apart faster than it took me to type all that!