Well, I keep restarting so it's hard to say. If I add up the hours that I've played with all characters, I'm approaching 70 hours. I've never even crossed into the western half of the map either
It's 20-24 hours to go everywhere, kill everything, do all the quests (as measured by the program). If you start over it can be as long as you like. I finished it twice in a real-time-week, and now I'm off to play Witcher.
I've got about 35 hours in and haven't done the easter eggs or the goblin citadel yet. I haven't been down to check out the lighthouse yet either, which I want to do before I hit the end.
I've spend a lot of time exploring and looking for that dang oak tree! Finally found the tree.. Thank the gods!
This has been the most fun I've gotten out of a game in a long time.
WOW I must be really taking my time - Have one quest still and 50.7hrs game time - gotta find that last egg - what the 4 or 5 chest need to open door and figure out shadowmirk - at least another 50hrs I'd say to do that