Arlo has been much more interested in the potty and the whole idea.
He watches Sam and though he rarely asks to go or tells us when he needs to go, he doesn't fight it when I take him. Last night I sat him on the potty before bed and he pooped! Then again this morning he made a little deposit on the potty. I think if I am persistent and regular about taking him, he could be fully potty trained by the time the new baby comes. We'll see how this winter plays out, but I am going to shoot for that.