But get your ticket early and be prepared to move very shortly after that to book an RV.
Smaller RVs sellout quicker (usually).
In addition to RV/Rental advice friendly rental places on burningman.com, search RV threads here on specific RV booking advice. Some have already booked their RV for 2012. Shouldn't be as critical for a truck (vs. RV), but again, search for Burner friendly truck rentals and when you should book by.
Premium fees renting RVs out of Reno (in some cases, $6,000 a week instead of $3,000 a week). Less but still possible for a premium from nearby cities. Significant savings can be had (regular fees) if you go as far away as Phoenix, but you have to be prepared for your time, gas cost, (possible mileage cost, rumor is some will rent unlimited), rental fees for the extra driving time, and wear & tear on the driver.
Odd. No bears to watch in the dump. Oh well, lets go across the road & pick blueberries.
... but don't harm the red dragon that frequents the area from time to time. He and I have an agreement.