For my 06, the dealer told me to change it out every 60k and to do a flush rather then a drain and fill. Their flush uses some kind of machine to force fluid from one to the other and it flushes the t/c while it's at it. The dealer quoted me $140 for the flush to be done. I've heard some folks say they took in their own fluid to the dealer (like Amsoil or Royal Purple) and the dealer used it instead of the stuff they stocked. Depends who you know out there i guess, i'm not sure.
As for the front and rear diff...nothing to it (I do a full cover removal, rather then crack, drain, seal up and fill back up as I like to inspect the insides). All I did was first i broke all the bolts lose on the diff cover and then continue working all the way around until you get some drips...then slowly work them off all the way around, starting at the bottom so that as the others loosen, the fluid starts to drain a bit faster. Once its done draining, pull the rest of the bolts off and remove the cover. Wipe the cover down with a clean rag and inspect the gasket as you will probably be reusing it . If you think there might be a problem, go get new ones...but usually you can reuse the original gasket unless it's torn or stretched. At this point, I like to inspect the gears and the "left overs" at the bottom of the pumpkin as this will tell me if stuff's been grinding off or not. Once I'm done with that, put the gasket back on the cover and line up a few bolts so that it's not slopping around while you're trying to get the cover back on. Screw in all your bolts by finger, screwing it in only a few threads (enough to hold the cover on) at first so that you can make sure all bolts make it through the gasket and once everything looks (or feels) good, then tighten them a bit more until all of the bolts have full finger resistance...then use your ratchet to finish up the job, criss-crossing like you would the bolt pattern on your rims. Torque them down to 30 ft-lbs at the end and then once you've filled your diff back up (see the line on the cover...that's where you fill it to), then put the plug back in and torque it back down to 24 ft-lbs. That's it...except I clean off the outside of my diff covers really good with anything that will evaporate after spraying it on and that way the next day, i can take a peak and watch for any leaks.
If you are not a fan of Amsoil, then the same numbers below will work...just make sure it's synthetic fluid, like what they put in from the factory. If you like the Amsoil product, you might chime in to the Amsoil dealers on here and find out what's best to your situation, but I believe I put their synthetic 75W-140 in my 04.5 because at the time i was doing some hauling with it, otherwise synthetic 75W-90 will do fine. Just depends on how much heat you expect to build up in there (towing vs. empty).
I think that's about it...anyone with any other additions or changes?