They're more different than you'd think. First off, the rear end of the Norco is far more suited to the coil shock. I thought about digging in to all the leverage ratio differences and whatnot, but the Norco manages to be just as plush, but without any concerns about bottoming out. If I'm at the top of a trail, I pick the Norco, no question. The Yeti is probably a bit happier on mellow stuff compared to the Norco, but if it's gnarly I'll take the rear end and geometry of the Norco every day.
But, if you are looking for something that is super capable but that you are going to climb a lot, the Yeti could be a good choice. It's a far, far superior climber.
Both fun bikes. If I was lighter and wealthier and liked to pick my way around Fromme, the Yeti could be a good all around Shore bike, but it's not as capable as the Norco. I would have loved to have had them back-to-back though, to better test that theory.