My Scanguage II on my 2001 Taco says my water temperature hovers around 188-194. That said, the stock thermostat is a 180 degree item. I have a 160 degree TRD thermostat in my Taco that came with my TRD S/C kit.

Based on this, your readings of 200-210 are probably about right for a stock 180 degree thermostat (remember that the thermostat on the 3.4 is in the water inlet to the block, instead of the water outlet -- meaning the temp at the outlet is going to be somewhat higher than the thermostat setting by the time the coolant circulates and carries some of the heat away from the engine).