I meant to set out on it, and ended up spending the entire evening exploring the northern coastline. Highlights:
Several small but surprising caves, including one featuring a jump that gave me vertigo.
Exploring a sunken ship.
Sniping mud crabs and plucking nirnroot at dawn.
Going into third person next to a dead mud crab and realizing just how enormous they are.
Zooming into the ultra slow-mo sniper mode with the bow, taking aim at a walking bandit from 50 yards away, leading the shot and one-shot him off a long stone bridge, sending him skittering through the air and along the ground. I find him later and see that I'd put the arrow through the bridge of his nose and out the back of his head. Freakin' bullseye.
Seeing the shadow of a bird, looking up and realizing that's no bird.
Discovering that my stealth skill is good enough to hide from a circling dragon, and watching it look for prey for 2-3 minutes before flying off into the distance. Beautiful and terrifying.
Standing on a rock spire on an island and watching the deep red/orange dusk settle in, and then turning around and literally gasping with awe at the mountains and mist reflecting it. Awesome, in every way.
Two hours just exploring the coastline. No questing, minimal looting, just exploration. And I'm thrilled with how enjoyable it was.
Skyrim is unrelentingly beautiful, and thoroughly brilliant.