We've got no overland vehicle, but we plan on doing the best we can with our 2004 Honda. We've been planning this trip for two years, but have achieved so much in the past few weeks. We got a Thule rooftop system with the largest cargo box we could comfortably accommodate, we have tents (and extras), sleeping pads and bags, our travel kitchen, etc.
Though we plan on camping about 60% of the time, much will depend on the weather. I guess we fear heat the most while we're in the south. We'd love to stay with anyone we can find when not camping and are up for just about anything. We have absolutely no set itinerary. Though we plan on making Philadelphia our first stop and Gettysburg out second, that's all we've got planned. We'll throw in anything that sounds exciting or is a "must", but keep in mind, our vehicle can't do what a lot of yours might be able to.
We're open to any and all suggestions! Great American Road Trip 2011