As I've mentioned before I've been 70 for a bit now. I managed to hit 70 before setting foot into Shadowmoon Valley.
I think Netherstorm and Shadowmoon Valley have the same level of mobs and quests, but the quests I did in Blade's Edge Mountains led me to Netherstorm and that's where I dinged. At that time I quit questing while I spent most of my time inside instances, getting attuned and raiding Karazhan.
Unless a quest sends me to an area I hadn't uncovered it. I simply haven't done much exploring, because there is always something else I want to do. Currently my main focus is mount money. So now I'm back to doing quests. I was worried that the quests would run out (my log was starting to fill up with heroic/dungeon/group quests), but just this past week I came across two groups of quests I didn't know existed in Netherstorm. One is Kirin'Var Village, the other a group of Ethereals (I don't recall the name). I'm looking forward to going back and finishing up those quests now. Not to mention you get extra gold when you hit 70 (because you can't get xp anymore).
In the back of my mind, I had this crazy idea of trying to complete every single quest available to me (except ones that required raiding objectives). There has even been a suggestion on the official forum to make all available quests show up as exclamation points - even after you've leveled out of them - the big discussion is what color the exclamation points should be, haha! (I say grey - but grey exclamation points mean something else - for the life of me I can't remember what at the moment!)
It would be helpful. Right before the Burning Crusade was released I had gotten bored enough to go to the gnome starter area on my night elf and do some of the quests there - yes even killing rockjaw troggs. I had to walk up to every NPC to see if they had a quest for me. I didn't make it far out of Coldridge Valley before giving up on that venture. Turns out I doubt I could complete every single quest - there are a lot o' quests in this game.
That leads me to wonder, how many quests ARE in WoW?
Preparing D&D adventures
7 hours ago