Nothing in the power-train is different. 2011 will give you the updated front clip, upgraded brakes all around, better front suspension design, and modern dash on in the inside. And way more useful door panels.
Note: Its pretty easy to swap the ''08+ front axle into the older vans. However if you are doing 4x4 it doesn't matter anyways, and while the rear brakes got upgrade the old ones should still be sufficient for most tires (up to about a 34" tire it seams).
2000 E450 dually V10 wagon