Update

Morgan is still doing pretty awesome with going potty in the toilet. But remember how I said I predicted that it wouldn't be a problem getting him to go number 2 in the toilet? Boy was I wrong. He just won't do it. He won't go in his underpants though, so that's good. But if we don't put a diaper on him, he'll go days without a BM.
Aaron even bought him a Hot Wheels car as motivation. It sits in it's package on the towel rack where Morgan can see it every time he's on the toilet. He really really wants to play with the car, but not enough to poop! Any tips from veteran potty trainers?
Also, Morgan doesn't say underpants, he calls them wonderpants. Which I think is about the cutest thing ever.
Oh, also, when should I stop putting him in a diaper for bed? He always wakes up dry...but what if?