I don't think the difference in mpg is that much. Maybe 1-2mpg. http://fueleconomy.gov/feg/Find.do?action=sbs&id=36627&id=36617^good to note. I dont plan on doing a whole lot of towing so the 4x4 interest is more for inclement weather and also for my volunteering with my local FD that brings me to some interesting areas. However I am leaning for the 4x2 due to the increased fuel economy, even if it is only 2-4mpg.
Honestly if I can get the 4x4 for the same price as the 4x2 with discounts then its a no brainer and I would go with the 4x4.