I'm at 29+ hours and almost at the end of the Sandship. That may seem like I'm way behind pace, but I've been taking my time playing the game and exploring the sky, finding whatever kind of sidequests I can. I also spent a decent amount of time treasure hunting in order to upgrade my Slinghot, Beetle, and shields (which, by the way, the Sacred Shield is perhaps the coolest shield ever besides the Hylian Shield -- it heals itself!!). I'm savoring every moment I can in this game rather than blazing through it in order to say I beat it. I've also come to the forums here to check out how everyone else is doing and to work on my review for the game, so that's taken a little bit out of my playtime. But it's mostly just me relishing the juicy, tender epicness of this game.
The actual story portion of my play is probably 24-25 hours.